So far, so good. Thanks!
Incidentally, turning off live scanning makes the compile run a LOT faster. In fact, I can pull up the AV control panel, disable scanning, run the compile, reenable scanning, then close the control panel, and STILL save time over compiling with AV enabled. I knew the AV imposed some latency, but I had no idea just how much. I'm going to contact them to see if they can whitelist using a wildcarded path since the Arduino build directory changes every time it starts.