David, it shows up on the page where you turn on the INDI server/Connect your devices. I leave the FITS viewer off... if I want to see a picture I use the ASTAP GUI to open the file.
It seems a waste to have these extra resources available for use while concurrently having new camera's coming out now with bigger sensors and not be able to take full advantage of the hardware. During this issue, I had like ~1.8-2gig or something free in memory. In essence I had *no* discernible memory exhaustion issue.