A 10-minute freeze is uncommon, but occasional drops below 20 fps may happen even with powerful systems. Might be interesting for the Challenger to adjust fuel flow based on the sim speed (which I suspect they already do for time acceleration, but maybe they're not using the one that accounts for time dilation)?
sim/time/sim_speed int y ratio This is the multiplier for real-time...1 = realtime, 2 = 2x, 0 = paused, etc.
sim/time/sim_speed_actual float n ratio The actual time-speed increase the sim has achieved - takes into account fps limiting.
sim/time/sim_speed_actual_ogl float n ratio The actual time-speed increase the sim has achieved - takes into account fps limiting and time dilation if fps<19.
…with the last one probably being able to work around the issue?
Regards,
Tim