The anonymous original poster has seemed very disappointed that more were not responding to his query, though with 19 anonymous responders (out of 26 total) it is not possible to know which of those may have been from the OP.
The OP did specifically ask about the SSPX experience, and I've never been to a SSPX chapel, the closest one to me being 150 miles away in Post Falls, Idaho. Still, I replied about my experience at the Spokane Diocese parish of Mary Queen of Heaven in Sprague, Washington, which has a High Mass (sung with Asperges Rite and incense) every Sunday at 10:30 AM ... the altar servers and congregation all kneel for the Confiteor. Yesterday I attended the second Sunday of every month High Mass in Walla Walla, Washington. It is normally at 2:00 PM at St. Patrick's parish but yesterday was at noon at St. Francis of Assisi parish. There were ten altar servers who, together with the congregation, ALL kneeled for the Prayers at the Foot of the Altar and Confiteor and kneeled at every other time prescribed by the rubrics (in my layperson's understanding of the rubrics and experience as a pre VII altar server way back when).
The first week of August I'll be in New Orleans for a meeting and looked to see where I might go to Mass that Sunday. The closest Catholic Church appears to be St. Patrick's, an easily walkable 1/2 mile, though I'm not sure what that may be like with the southern August humidity ... I'm used to the dry heat of the eastern Washington desert. There is a public transit connection I may take advantage of. St. Patrick's has a 1962 Missal Mass at 9:15 AM. For the benefit of the OP I'll be happy to report back as to the posture of the altar servers during the Confiteor.