I see. I remember someone on the construct community discord was tinkering around with this idea, I don´t remember who it was though. I think it could´ve been Skymen.
But your best bet is actually limiting the amount of layers and handling it like dop2000 suggested. I don´t know what you intend to let people create with it but there is likely an upper limit of layers that a user actually requires.
It may be possible to create some sort of rudimentary layer system with the z-order of objects. Create a Sprite that acts as a "Layer" and use the Z-Order action to "Move to object > in front" to move it on that "Layer".