Thats why the one-off scenarios usually have the wind layer set to keep you below 30K.
Besides, most AH planes don't seem to me like they fly "right" above about 25K anyway, I've caught 109s wallowing (or been the wallower) above that when they should have been flying rings around any USAAF fighters in the setup. Heck, I've had WEP on in a G6 and at that height its all I can do to maintain a 1K climb with DT and gondolas.