Thank you so much for that advice!
I rolled my system back, removed some other stuff, timed startup and then reinstalled Avast and established that it added about 30 seconds to startup. Removing those components actually added another 20seconds to startup. I added them back and startup was back down to 45 seconds. Strange. Maybe it has something to do with the restore point it creates but I'm doing two restarts and timing the second because I assume the first involves some system changes.
Anyway, it's way better now than what I was getting when I first hit this snag.