You could use XT30 or XT60 connectors to sepparate the PSU from the Einsy. I have done it myself a few years ago on 4 Prusa's and it is working great. But I've only got the +/- cables, no power panic though.
The YL connectors are rated for wires as small as AWG 26 (and as big as AWG 16). If the power panic wires are smaller than this (or the power supply wires larger) you will need to use a different connector for them. Otherwise, I do not see a problem with mixing different wire gauges in the same connector.