MSFS Addon Linker sounds like a great idea. Will it also work with MFSX or is it a MSFS exclusive.
In P3D4+, there's no need for something like that, because you can just disable/enable add-ons from the Options->Add-one menu, at least the proper ones that use the add-on.xml method.
In FSX, a tool like that would be *way* more complex, because there was no suggested standard to clearly indicate all files in a product like the add-on.xml in P3D4/5 or the "package" method in MSFS, it's a big mess of a wild-west there, files can be spread everywhere, even inside the simulator own folder so, a tool to manage them all, regardless of the add-on and the developer would be extremely complex and unreliable, which explains why nobody ever tried to write it.