I had wondered the same. However, so far as I can tell, running without Berryboot has yielded a perfectly fine installation of Patchbox/Pisound. I haven’t progressed any further with trying to get Berryboot working because I’ve been playing music all night (finally)! Bluetooth and WiFi are working just fine.
So now I have a quandary: because the touchscreen housing (not the full-metal heat sink) prevents me from getting to the SD card when fully assembled, I seem to have no way to switch back and forth between other distros and at least Patchbox specifically. Berryboot seemingly offers a solution and unlike NOOBS, supposedly allows you to boot from a thumb drive. I have not explored that option yet, nor have I looked into the RPi4 firmware update that supposedly incorporates that capability directly in the PI. In reading the thread on the RPi4 firmware update, you (Giedrius) mention the possibility of having to recompile Patchbox with with the regular kernal (Support for boot from USB? Pi 4b). In using the “adding custom distributions” process of incorporating Patchbox into Berryboot solution, would I be mistaken to say that this process might also swap out the Patchbox kernal for one provided via Berryboot? I’m left wondering if the cost of having a bootloader on the SD card or even booting from a USB stick is ultimately going to come back around and impact the low latency performance that’s the hallmark of Patchbox? I’d love to resolve this ‘bootloader quandry’ so that I can get on with the ‘meat and potatoes’ work I hope to accomplish with the Pisound, but I’m starting to wonder what the cost of resolving this problem will be vs moving on with a single purpose RPi4 box? I feel that would be a very inconvenient solution, but one I’ll accept if there’s presently no better solution worth pursuing. However, it also feels like this nut is half cracked and I shouldn’t give up yet. Maybe getting this right will help others along the way.