I'm not sure if you are asking if it was possible for GSX NOT update the cache at all, which is clearly not possible, since it must do it when an AFCAD changes, or if you want to find a way for not doing it manually.
The reason for having to do it manually, it's related to the way GSX checks for file modifications: which is NOT checking each and every file, one by one but, instead, checking the time for the last modification date for each scenery *folder*, which is many times faster than checking each single file.
The downside of this, is that Windows doesn't change the last modification date for a folder, if you just rename files inside of it, so you must trigger a manual cache rebuild in this case.
Having to choose between a *much* slower cache rebuild time in every situation and having to manually trigger a regeneration after a file rename, we obviously chose the fastest solution, since most of the sceneries out there don't have multiple AFCAD that keeps changing, so we clearly gave priority to the most common case.
If your issue it's just that doing a cache regeneration is annoying or slow (regardless if you do it manually or not), you can speed up the time required (by a factor of 10x in certain cases), by adding the whole simulator folder to the list of the antivirus exclusion and, if you have sceneries installed outside the sim folder, add them too.
