I don't like the T hand placement (mostly for myself I mean) but it shouldn't be that hard to adjust. I feel like my main problem with it is you do cartwheel to side HS and don't turn in and at some levels I just find it too confusing for some girls to switch off (mainly the younger ones who are a little all over the place). It helps some so I intro it as necessary...otherwise I let them put their hands straight. I spot a lot to get a fast CW and I find the T placement slows it down for some girls who try to be too deliberate about it. Which is actually ideal in some circumstances when you're trying to get them more in control just to do a single CW on beam like in the L5 routine, but I start teaching it early and I train it pretty fast with a spot for quite some time. I'd rather they do it fast and tight and occasionally fall in L5, than do some of slow-mo ones I've seen and stay on. Ideally you have a consistent speed and control throughout but we are talking about an intro level so you can't always have it all. But everyone has a different end in mind and even for different individuals I'm okay with different things.
I definitely don't turn my second hand in on floor tumbling or tsuks either, and I was pretty high level. I'm not saying it doesn't work because I do believe it to probably be mechanically a basic sound idea, but I guess it's just not something I stress for every single kid in gymnastics and I don't think having both hands side vastly hinders you or something. It's a little strange because I find myself doing it with cheer more because we do a ton of RO drills early and a lot of kids don't turn sufficiently, but in gymnastics I rarely have this as my biggest problems. My focus on floor and beam is strong kick over the top and quick chest rise at the end. Arms by the ears going in - correct reach and kick "forward" first without turning out early. End of single CW needs strong lunge without stepping in or having the feet too close together, eyes toward the end of the beam, chest "anchored" in relation to the beam. Kick drills and work are important to me. Lack of flexibility through the back kick/hamstrings with the base leg and the first leg coming down hinders this.