Agree, if you only pully the plugs out the back of mib1 should be fine - but most workshop manuals will tell you to disconnect the battery before carrying out work on the electrical system.
If you take out and disconnect the glove box for example you need to disconnect the battery other wise you will trigger a fault code.
Problem today is the folding mirrors so you have to retrain them if you disconnect the power and windows controls go out. If its some minor thing where you aren't going to disconnect the air bags. Disconnecting the air bags is power off else you have to clear the error code. If you are likely to short circuit something power off. But for removing a mib unit is fine, if it's plugs and sockets... anything more disconnect the battery but then it's retraining the mirrors and windows after. The classic one is people putting in cameras and disconnecting the air bag to bury the lead without disconnecting the battery, that's disconnect the battery else you are recoding for the air bag warning.
Because we didn't want the hassle did it how the mib2 retrofitters do it. Keys, slide forward, fingers round the back and remove the plug via the leaver gadget thing as I remember. Moral behind it if you got an Arona you can't see where the SD slot from the seat. Changing SD cards you do by touch. You find the slot and run your finger across to find the second slot then all is good
. My name was muck after I had the accident.
Ateca and suspect the Leon you can see the slots
.