Playing games with TSX ECUs

[Populuxe]

I feel as if I'm beating a dead horse on this forum, considering Hondata is so tight-lipped about their products. Whether details aren't shared for trade-secret or legal reasons I'm not sure, but some insight into things would be absolutely awesome here. Because I can't seem to tune the '07 TSX whatsoever (don't have a K-Pro, which I'd really prefer, I don't have a Reflash, don't have any of the fun Hondata goodies that even make tuning possible,) I've decided to play around with ECUs. From what I've found online, the part number on the '07 ECU is 37820-RBB-A21, while the old '06 ECU is A04. The A04 is currently flashable while the A21 appears never to be (for some reason unknown to me, as I don't have both ECUs sitting in front of me.)

Pretty much, I should be able to swap the A21 where the A04 is, and retain usable functionality, minus the TPMS technology. But why the lack of 'recommendation' in this case? Is it simply for liability reasons, or are the fuel / cam / other engine control maps really different between the A04 and/or A21 ECUs? I take it you guys have been able to mess around with both of them, and unless the A21 is a total black-box, have some idea of the functionality both of them have.

I guess I have two options: try it and see if my K24 goes boom (which likely it won't) or go get something F22C-powered instead. Or, maybe, in a rare case, Hondata will shed some light onto the A04/A21 disparity. (Maybe I can also dream of a K-Pro that works properly with the TSX?)