Requesting the ability to independently bind LT and LB. This should then "grey out" the option to keybind the affected button combinations; e.g. if you bind LT to Shift, you can no longer bind LT+Y or LB+LT+A, but your LB+X binding would be unaffected.

The intention is to offer an option allowing the keybinds to better fit with a modifier-macro-based keybinding configuration.

This already exists. All you have to do is clear the combination of the button that you would like to use for modifier macros.

E.g. if you want to use B as your base binding, then just clear LT+B by right clicking on it in the binding config. This will make that binding default to the base binding and allow you to use modifier macros.