Thank you for this very helpful guide. However I fail to see why you would conclude that replacing the battery is 'moderate'. Could you elaborate on this a little bit more, please?

For me 'moderate' means it is (very) complicated (i.e. plenty of steps) but feasible in general (i.e. there is a good chance you're not gonna brick your device) for which there is only one escalation level left: 'not feasible at all'. Non of that is true for the FP4. Could removing the battery more user-friendly, though? Well yes, of course but it is still by far very simple and straight forward.

Again, thank you very much for this great contribution.