Great video! I don't entirely agree that spring is the only key time. In my experience, Great Lakes smallmouth are fat as heck almost year round, save winter when I've never fished for them or directly spawn/post-spawn (see pics below). My PB came on a warm November day, in a deep wintering hole on Erie. I do have some outstanding catches from pre-spawn and spawn periods, as well as dead of summer.
June, directly post-spawn
Novemeber:
Early May, minutes from spawn. Males were already making nests:
August (a few decades ago, lol):
Late May, full on spawn: