Just wanted to share…
For anyone looking for an easy and convenient way to battery power the PiSound with RPi4 , I found out that Anker Nano Power Bank 5000mAh is a great option.
It has integraded usb-c in/out male connector that lines up perfectly (height-wise) with the RPi4 charging port in PiSound case, so you can just slide it in on the desk. You can even pick it up and it won’t fall out, although for some serious manipulation I’d probably secure it with some rubber band, just in case.
It gives 5V3A and so far I had no power issues or warnings even while using some power intensive patches and some usb peripherals. It also has usb-c female in/out connector that you can use for passthrough charging.
The only downside I see is that it obstructs HDMI ports and it might also clash with some thick jack connectors (in such case it is possible to fold the usb-c connector a little bit). But so far the cables I used worked out fine.
