I second this request, and also that it would keep that spot open from any respawned aircraft.
So right now, when you look for gates in the GSX menu, it lists the gates by numbers and whether it's occupied or not - selecting an occupied gate would "free" that up for you, and keep it freed up.
This is my #1 pain point with GSX at the moment, spending many minutes trying to find parking when I should be doing my after landing flow checks.
Thanks for any consideration here,
Daniel