i've just watched the clone wars episode where Anakin, Obi-Wan and Ahsoka meet the for lack of a better word the force deities, one of the abilities that they posses is where they can deactivate and presumably activate lightsabers at will while i believe that doing this with any lightsaber is OP as ****, having the ability to do this with 1 or 2 lightsabers the character owns could be very nice and so in my games i have added to each crystal a tallent, costing 25 EXP an additional "oath" to gain (this part comes straight from stormlight archives), called "Over Attune" its effects are as such:
Ignore lightside and dark side restrictions on this crystal (there's only two that i know of that have is qualification), may activate or deactivate a lightsaber with this crystal installed at will
feel free to use this in your games if you feel it is appropriate