It's essentially what they've done all year. Ullmark has 42 starts to Swayman's 27. A lot of the difference is from early in they year when Swayman got off to a bumpy start and then missed 3 weeks with an injury. Since Swayman returned on 11/19 the workload has been 29 appearances for Ullmark and 26 for Swayman. They've been in this every other rhythym since essentially Thanksgiving. It's clearly working as one is going to win the Vezina in all likelihood and the other hasn't given up a goal in a few games. I don't really see the need to stop doing it so long as both guys are performing at their current level. It's part of what has made them so successful this year, why not take advantage of having two good goalies and keeping them as fresh as possible?This is a great question. I also wonder if shifting the workload to 100% would negatively impact Ullmark too. Probably not, but it's a variable that doesn't exist now. I think I'm in favor of this approach, and would guess that Ullmark and Swayman are the right duo to do it with.
What a good problem to have. "Both are goalies are playing too well to sit."
I just don't recall a team wilfully rotating in the playoffs so as I said it'd be against conventional wisdom. Teams have won Cups using multiple goalies but it's typically injury related.