iPad Pro m1. The only config change I had to make was 'enable background audio' in the devices menu. No issues running ForScore full screen, no lag no crashes. Focusrite 2i2 audio interface.

However, if I run Pianoteq 8 and ForScore on an iPad Pro M4, I get too much lag and some distortion, even crashes.

Ultimately, I would like advice how to configure Pianoteq 8 on iPad to run simultaneously with other apps, such as ForScore and ToneStack Pro, using multitasking and Stage in the latest iOS versions.

Or, should I be using AUM to run Pianoteq 8 and Tonestack Pro simultaneously?  Would running ForScore in the foreground to read sheet music interfere with AUM in this case?

UPDATE:  I succeeded in running Pianoteq 8 and Tonestack Pro in AUM and they work very nicely together, though the buffer size changes to 256 and the sample rate can go no higher than 48000 Hz.  Latency is OK.  However, bringing up ForScore does degrade the Pianoteq 8 sound quality, but not the ToneStack Pro quality.  Turning off "Multicore rendering" in Pianoteq 8 seemed to help slightly.