Apparently the ar234 can be coaxed up to super high altitude with a great deal of difficulty though it can't be done with ordnance on board.
I found it in the training arena with fuel burn 1.0 so I tried it in the latewar main arena last night with fuel burn 2.0
This greatly angered a pilot who upped a 163 and could not reach the 42k altitude I was flying at the time so I apologize for his only being able to get half the altitude out of a 163 that others can.
The 234's critical mach and stall speed are very close above 50k feet so it's not like you can maintain 60k feet other than for a few seconds from a zoom climb that quickly turns into a nose down mushing stall where sink rate is only stopped by the time you have descended to around 40k.
Then you're out of fuel.
The drop tanks seem to do nothing as fuel selection only goes between the internal tanks and not the drop tanks.
You can select them to be dropped.
