I think reducing it 4 layers may be best, but I'd really say that @jackhumbert should have the final say on that.     And the keycodes listed do the tri-layer stuff. Oh, sorry, they're `FN_MO13` and `FN_MO23`.  https://github.com/qmk/qmk_firmware/blob/135d28d2fb3234dab3ef5353b47ec5838534e39d/quantum/via.c#L163-L183