hello
@France_ja
a warm welcome to DTP
I wonder whether it's possible to box off/cover over the controls so your brother in law cannot see them ... with my dad, if something was out of sight or didn't look like a control/socket he left it alone ... I had to cover over any standby lights too, or he went looking for why they were on
or even have a new control system installed, hidden away, possibly even with remote control of some kind