I 'm currently looking at some additional use cases for the 4 channel Beocreate board. One such an application is a 2.1 with extra sub powered from your AMP2, or connected active via Digi+. It would be possible to create a 5 channel AMP with full DSP control on all drivers.. (2x 30W for high, 2x 60W for mid/low + 1x60W for sub).
Did you by any chance make the Beocreate GPIO 34 pin header compatible with the key GPIO's of i.e the AMP2? Channel 2 I2S out could be used via the 34 pinheader to drive the AMP2, with initial setup via RPI. If not something to consider for a next release :-).
Just my 2cts.