I’m not thinking g it matters all that much at those sort of pseudo speeds.
If you don’t want to manually double the bpm using engine primes existing feature of “ x 2 “ which must be there as the solution for this situation, then simply modify the loop lengths and effect lengths that you select live when playing tracks.
So if you know that the well known ( ! ) Ultra-hyper-terror-jungle track should be 400 BPM bit Engine prime says it’s 200 BPM, then if you want a 8 beat loop, choose a 4 beat loop, as 4 beats @ 200bpm lasts the same amount of time as 8 beats @ 400bpm.