In my BKSQ Caravan using PMS50 GTN750 (latest version as of the time of this post) with the extra WTT-package 1.0.7 for AP/flight plan installed. A few updates ago, PMS50 stated that the WT-layer had a major update. Ever since then the AP remains lit when disabled. (i.e. ROL mode shown, etc.) However, the AP is not engaged in roll or pitch, just that some of the lights on the KAP140 display and the AP annunciator panel remain lit. I do have the systems.cfg and KAP140.js changes applied. Before the aforementioned PMS50 update and with your recommended bug-workarounds, the AP worked most of the time flawlessly, including no lights when disabled. It appears to just be a visual problem, AP works as expected (some bugs perhaps occasionally with weird altitude tracking overshoots still but that's another issue). I'm still on SU14, maybe SU15 will change something.