This question was not focused on the SSPX specifically, only that their founder posed the “Experiment of Tradition”.  With that said, the true Tradition that you imply does not seem to be flourishing…even after nearly 12 years since the Resistance and decades of other Traditional groups.  It would seem that Gods grace is not overflowing as one would expect.

https://www.clevescene.com/news/blessed-other-1472603

Soon after the visions began, Mary began appearing to Sweeney-Kyle daily, offering personal advice on cooking, prayer, and shopping, along with messages to be shared with the prayer group.
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A few people worried that Sweeney-Kyle might be confusing fantasy with reality to win friends.  They suggested that she present the advice as her own — not as the Blessed Mother's — and they say that, on occasion, Sweeney-Kyle privately admitted she made up some of Mary's maxims.
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While the church stayed silent, the messages from heaven were getting juicier — with the Blessed Mother making predictions and micromanagement decisions. One message had Mary proclaiming that Boris Yeltsin was the Antichrist. Another decreed that then-President George Bush would be reelected in 1992. When those "divine proclamations" turned out to be wrong, Sweeney-Kyle would try to smooth things over by saying that she had misinterpreted Mary's messages, chalking it up to the imperfections of a mere mortal.
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… [Donald] Kyle met Maureen in Fort Myers, Florida, where she was speaking to his prayer group. A former Middleburg Heights policeman who retired in his thirties because of a work-related disability, he moved back to Cleveland to live with his mother and became Maureen's unofficial chauffeur. Early in the morning, he would pull up to her North Ridgeville home, sit in his car, and wait while Maureen's then-husband, Paul, left for work.

"Why was he driving her around?" wonders one former associate. "She knew how to drive. Why didn't she drive herself?"

Because she was frail and sickly, says Shirley Kane, who was a member of the inner circle early on, but left for health reasons of her own. "She needed someone with her," Kane says, calling Sweeney-Kyle a "victim soul."

Kane recalls that Sweeney-Kyle would be in the middle of a "nice conversation" when she would be gripped by a seizure and have to be carried upstairs, by Kyle and a few other men. When she was receiving a message, Maureen would often collapse in front of the group. Her attendants would apply ice packs to her neck, and the ice would reportedly melt faster than normal.

Not everyone thought Sweeney-Kyle's illnesses were legitimate. "She went through a period where she pretended to have epilepsy," says one source. "She loves to talk about medicine, loves to take medicine. But once the divorce [from her first husband] took place, the epilepsy went away."
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Kyle's fawning attentions also bothered some observers. "Maureen thought he was very attractive, talked about him all the time," says one source. "Don would have to carry her everywhere. She was infatuated with him — this is a messenger of the Blessed Mother — and she was married."

"[Kyle] was there to be her protector from anybody outside of the circle," another observer recalls.

Paul, Maureen's husband of 25 years and an active parishioner at St. Brendan's, was skeptical of the ministry from the beginning. He attended a few of the group's early meetings, but though he was a devout Catholic, he had no interest in becoming more involved. Once Kyle took up vigil in the car outside their home, Paul told Maureen that he didn't want Kyle ever coming in the house.

Donald Kyle took a roundabout road from police officer to visionary handler, with a short detour as a self-appointed pro golfer named Brandon Kyle. Born and raised in Brooklyn and a graduate of St. Ignatius High School, he and his first wife, Mary Lou, married and divorced twice in the 1960s and '70s. According to court records, the second divorce was especially messy — Kyle admitted to having an affair with Debra Nolan, a woman he had met on duty at a traffic accident. His first wife filed a restraining order, charging that Kyle was abusive. But Kyle apparently took a few hits himself.
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Kyle, who also married and divorced Nolan, retired from the Middleburg Heights police in 1985 and moved to Florida. He had a clean record as a cop and an unusual work-related injury: He'd shot himself in the foot on a domestic violence call.

"Nobody missed him when he left," notes one former police colleague. "He'd gotten so strange."

Though he tended to lecture criminals, Kyle was an otherwise model cop from the time he joined the force in 1973 until about 1981. Then he started going to Mass while on duty, taking lengthy coffee breaks at church, and proselytizing to his co-workers. Kyle told colleagues that his two-year-old son spoke in tongues and knew several different languages. At one point he started calling himself Brandon Kyle ("It sounded cooler," recalls one cop) and passed out business cards that read "Golf Lessons: Brandon Kyle." He told co-workers that he was leaving for Florida to make money on …

By the early 1990s, Sweeney-Kyle was spending less time with her husband and a lot more time with Donald Kyle. Once, she asked Paul to accompany her to a speaking engagement in Florida. Kyle made the trip with them. In Florida, Maureen and Don were inseparable, leading prayer services together in the host couple's living room, while Paul was left wondering what had possessed him to come.

Soon after the fated trip to Florida, in the summer of 1993, Maureen moved out of the house and filed for separation. Several months later, Paul filed for a divorce, which was granted in May 1995.

Maureen then began trying to persuade a reluctant Don to marry her, says one insider. "[Don] was infatuated by the ministry and loved the power she had," says the source. "He wasn't the one talking marriage."

Past and present members of the group believe that the Blessed Mother, and the ensuing ministry, came between Maureen and Paul. Some regard the divorce as the inevitable end to a visionary's former, more ordinary life. "You're never a prophet in your own home," says Kane.

Others found it more tragic.

"If you're getting these messages, and they're real, why don't they tell you to spend some time taking care of your marriage?" asks one observer. "You'd think that someone who was Catholic would have told her, "It's important for you to stay married.'"

Don and Maureen were married in February 1997. It was Don's fourth marriage (his previous ones had been annulled). Father Frank Kenney, the ministry's fourth spiritual adviser, officiated.

We at Holy Love ministries are, and always have been, an ecuмenical ministry. We have no affiliation with the Diocese of Cleveland.