Trying to make a puck js doorbell and need advice on range

Great! Glad you got it sorted! Being able to use USB3 for your SSD would be nice - what about putting the BLE dongle on an extension lead and getting it as far away from other electrical stuff as possible? They're not very picky so any old extension is fine.

Then, because your Pi is just using Ethernet anyway, you could put the whole Pi+SSD in a metal box to shield it, and that should really help?

Should I be using E.getBattery or Puck.getBatteryPercentage for the battery levels?

It makes no difference, they are the same (but I'd use E.getBattery). Puck.getBatteryPercentage was done first, but then I realised it was handy to have a E.getBattery on every device with a battery, so you didn't have to have Bangle.getBattery, Pixl.getBattery/etc.

I thought I'd marked Puck.getBatteryPercentage as deprecated, but maybe not - I'll mention it in the docs.