Solution from Hyunah Baek @ Autodesk
After further investigation, I found that it is possible to add hotkeys by modifying ./Plugins/Mu/shotgrid_mode.mu file.
Please try adding the following code around line 2464 to this file and check if the hotkey is applied as expected:
app_utils.bind("key-down--<key>", changeEdit("all", Prefs.PrefLoadRangeFull,), "Load Range Full");
app_utils.bind("key-down--<key>", changeEdit("all", Prefs.PrefLoadRangeCut,), "Load Range Cut");