Belated thanks, Captain Dawson.
My own experiments have been going well so far. The player aircraft can indeed be changed out using the BAT briefing page. To date I've only tried this in WAW, with the P-51R, the F8F racer, and the F2G. The shots below are from the "MYTHIC Ring jour" mission:
For those not familiar with these missions, all were originally produced with air starts involving a TB-3-Zveno carrier bomber and an SPB version of the I-16. A replacement type for the I-16 will spawn separately, but of course the bomber still appears. The bomber is eminently ignorable, but if I were to rework the missions, I'd be inclined to produce a version of each with the bomber deleted:
It looks as if, for reworked missions, at least some of the objects forming the course might have to be shifted in order to accomodate aircraft larger than the I-16, a tedious but do-able job. In fact, I've had yet to work up the nerve to try flying even an F8F between the pylons, let alone a machine as big as the F2G. Some of the turn radii may have to be enlarged as well. The main thing is that the maps do work in BAT, the player aircraft can be changed, and I'm guessing that the maps would work in DOF, TGA. and JTW.
EDIT: I just altered that last sentence. It's occurred to me that since the player aircraft is an I-16 Type 24, the missions as originally produced might not come up in DOF and JTW. The SPB versions of the TB-3 and I-16 are, however, included in TGA, so the missions should work there. In theory, anyway.