Q_TAILSIT_INPUT is ignored In QACRO mode; the roll and yaw sticks always command body-frame roll and yaw rate. There should be no functional changes in QACRO between the branch you have been flying and this new PR.
The new PR is just a subset of the previous branch, including only the new versions of ATT_THR and BOOST gain scaling. Since an older version of those was already in master, this is a smaller change to master than before.
So this PR leaves GAIN_INTERP and Q_ASSIST to be added as the next one or two steps. I’m actually not sure I understand how q_assist works with a tailsitter, since there is not an extra set of motors to “assist”.
frame_class will still be 10 for dual-motor tailsitters, or 1 for a copter tailsitter with non-zero q_tailsit_motmx, as before. And q_tailsit_gscmsk = 1, 2 (and 3) are all supported.