Exactly. If you leave it at 65% it won´t fire unless you are really close to use all your RAM. This is how I have it. Also check the last row. I have it on 20Gb. With those two conditions start game and just in the airport force the smart trim manally. You will see how around 5Gb are cleared inmeditally, which are the result of the flight launch. Just leave it alone and it will take care of having your system healthy.
I have performance mode enabled and probalance as well but I excluded MSFS from probalance as it will set the process priority to below normal if you change to other windows. I just prefer that MSFS is always running at normal priority while the rest of apps on the background are the ones being managed by probalance. That avoids some stuttering I face in the past for instance.
Cheers