I don't believe the Ta-152H has the speed to catch the B-29 up there.
Wiki says 33K and 357 mph. Had a Spit 14 up there a few days ago. TAS was somewhere around 440-420. N jug, TA 152, and dunno about the 262. Other planes also fly fast enough at 20k to run down anything chugging along at 360 TAS in round figures. Oh, also had a TA 152 up at 35k escorting a few weeks ago. Way fast.
B29 with proper load out for AH would be wonderful. Period. HTC could trick it up so the door do not open below 25K or 15K or whatever alt they say.
Also, i don't know how the guns worked, but HTC could make them "work" for the world of AH. It's rate of climb at 900 feet per min is inline with our current buffs.
For grins, I have a pony at 33k right now in the MA. 410 TAS with 1 left showing on the climb line in e6b. according to speed charts, pony is much faster at 25k. Pony, N Jug, and TA152 are fast enough to run down a 29. At 25 to 20k, then even more join the chase.