Hi @final,
If you already know upfront, that you’re going to rely on GPIO I would not suggest using a x86. We did some test for the MPD_OLED plugin on a x86 using the DollaTek CH341A.
Every plugin that relies on rPI libraries will be problematic and need to be recompiled from source.
With your requirements, step motor, IR and volume control, I would go for a rPi.