We've considered this in ways before, mostly to ensure up to date code.
If I remember correctly, I think we always decide 'no, it's kind of an invasive idea'
XGUI loaded?/loads a 'list' of some sort from our site, or at least, 'did' at one time, called sbox_cvars.txt
Though not a true count, statistics for page loads are available through our host.
Wouldn't show true users, but might show how many times servers are restarted, or at least, installed once.
Stickly, that file still loaded dynamically first time XGUI intalled/server reboot?
Meg, I've lost my username/pass for logging into /stats. Mind emailing it to me?