I'd agree can quick change in minutes but we've done it before, although you wouldn't have let the neighbours know...
Did the right thing there, you have told them you have a working system and you don't want/expect it to cry wolf.
Although bell can be reconnected within a min or two of you skilled enough
I would have let the old panel hand some how cut the plastic or something got the new back plates in and powered up may odd disconnect but it would have been quick
15min ringing you letting the kettle boil
This is the reason you use proper gear. Diy stuff can be disabled but what would you prefer an off switch? Or worse an off code.
You have found out that compliant equipment does as it says.
Depends how it's all wired tho, if your going to take time you can disconnect and send power to it via a battery , otherwise as above I guess
Keep windows and doors closed that way it doesn't bother you lol