Nothing in that video seems to indicate the stuttering it's *caused* by GSX.
With the next to last update, GSX was stuttering *itself* (NOT affecting the sim), because when users had low fps (less than 30 fps), it might miss some animation updates for its own vehicles, because it was self-limiting to not update itself more than 30 times per second, while before it was updating as fast as the frame rate.
This was made to prevent GSX to send too many commands to Simconnect, precisely to not to be too intrusive and not risk affecting other addons.
However, this was really useful only if your frame rate was much higher than 30 fps, otherwise it wouldn't make any difference.
So, the LAST update, made this setting optional (it's in the Addon Manager options, the "cap Simconnect updates" setting, which is disabled by default, so by default, GSX works exactly as it always was.
So, theoretically, if the stuttering you had WAS caused by GSX, it should always been like that, because that's how GSX always worked. You can try that option, and see if it makes any difference for you.
Of course, I assume you DO have the last update (released April 5th), which does have the option.