Other day I was at 32k as the only defender in a 47N against boxes of B24 and B17 escorted by 51's and 38's. Fighting at that alt is a whole other reality.
What about an LW arena that has some number of fields with 25k air starts to enable high alt combat without encurring 30+ minutes by the buffs to reach 25k? Place multiple big strat targets in the back feild of each country that have to be at some percentage reduced befor a map can be reset with base captures. Possibly make these feilds harder to disable and capture.
Put the same perk price on the 163 that is on the 262 or double it. Put really heavy ack in the strat targets and around them.
Call the arena "Phoney High Altitiude Air Start - Enter at your imagination's risk".