An old adage that is particularly apt when it comes to miraculous Novus Ordo Indult-only trad conversions: If it sounds too good to be true, it probably is.
Buuut... Muh VII truth filter!
Let it die. Vigano, like Tɾυmρ may bring a certain amount of relief and hope to starving ears but there's a rainbow flag at the end of that pot 'o shekels.
I think +Vigano stands out among all the rest of "indult only" conversions.
1) He's already stated his opposition to V2 and the innovative/abusive new mass. So, if he privately says the TLM, what kind of "indult" is that? It's not an indult at all, for he disagrees with every "condition" of +Benedict's "motu" and has stated his support of Quo Primum.
2) Let's give Marshall and all these recent indult-converts some leeway. Many of them are totally new to Catholicism, in general, AND to Tradition. Marshall admitted that he used to hate +Lefevbre and the sspx because he looked upon them as similar to Martin Luther, who rejected the Church, and many "normal" catholics he talked to, told him the sspx was schismatic. Fast forward to now, and he had admitted he was wrong, sees why Tradition exists and now supports +Vigano's cast-it-all-out approach to V2, as opposed to Schneider's "let keep trying to fix a square circle" approach. I see a lot of good will in Marshall.
3) I don't know much about Opus Dei, except they are a big organization with dubious beginnings and a questionable orthodoxy. Does this mean that EVERY member is "in on it"? And if Marshall is corrupted, how so? What's the goal? What has he done that's wrong? He's an anglican convert that joined Opus Dei...maybe he makes good money and they wanted his contributions? There's a lot of "useful idiots" in these groups (including the masons), who invite "popular" people so their groups appear mainstream, and many of these "popular" people have no idea they're being used.