When I fly GA, I don't use GSX, so I unlink both the main folder and the jetways folder in Addon Linker. However, the Couatl engine still runs (sometimes with up to 20% CPU usage).
Your error is that you are using the Addon Linker to unlink, which just unlink the Community packages and this is CAUSING the Couatl engine to run in an abnormal state, using more CPU than normal (it never takes more than 2-3% of spare cycles from free cores when the packages are enabled).
That's why, there's a proper Unlink function in the FSDT Installer, which doesn't simply unlink the two community packages, but ALSO disables the Couatl engine from starting in the EXE.XML, and that's why you should always Relink with the FSDT Installer as well, because when relinking, not only the Couatl engine will be re-enabled to start with the sim but, the jetway exclusions will be reconfigured again, in case you installed NEW airports while GSX was inactive.
All these extra steps are not known to the Addon Linker, which is generic, that's why we have our proper Unlink method instead.