Hot take: mitering outside corners on baseboard is worth the extra time, my old boss was wrong
Back in 2018 my old boss Rick told me coped inside corners were the only thing that mattered and outside corners should just get a 45 and some caulk, said nobody would ever notice. So I did it his way for two years on trim jobs around Springfield, and every single outside corner opened up the first dry winter, especially on that 1890s house with plaster walls that moved like a boat. I switched to mitering and gluing outsides with a spline about six months ago and not one has cracked on me since. Rick still swears caulk is fine, but I've got a call back list that says different. Any of you spline your outside miters or am I overdoing it?
A little caulk on an outside corner is normal practice though, plenty of old houses been holding up fine that way. Sounds more like the plaster walls moving is the real issue, not the caulk itself.