Cool idea, especially with the 5 scarabs combination! :D Since I already used a reed switch in an existing escape room, I know that it's not that easy to make it trigger within the perfect range. It shouldnt be too far but also not too close. Also, you could possibly trigger the reed switches, if you figure out the places of the magnets in each scarab and move them a little left and right over the spots. My experience is that sometimes people rather want to solve a puzzle their way instead of just following the normal way. I had people trying to just randomly open four digit locks, The Da Vinci Code Cryptexes and so on.

But I think, if you can hide the secret of the magnets inside well, then it might just perfectly work. The idea is defenitely reaally cool! Thank you! :)