Cap dumping Holmes would be incredibly stupid. You don't need to yet. They already have tremendous flexibility. Even if they didn't dump Holmes in the next 2 years (which seems pretty likely), the only salary on the books right now for next off-season is the 32 mil to Fox, 18 mil to Sabonis, 5 mil to Davion, and like 6.5mil for the #4 pick. or $61.5 mil overall. Holmes would bring that to $73.5 mil. Let's assume DDV gets $10 mil/season and we spend the full $10 mil MLE. Would put us at $93.5 mil that off-season and with the Salary cap being $121mil this off-season, it's safe to assume it'll be around the $125 mil range in the 23-24 off-season.
Basically, you're freeing up an extra $12 mil in FA in an off-season we'll have 30+mil to work with anyway. And that's assuming we use our full MLE and DDV gets a $10 mil contract. Which.. doesn't make sense to me. Holmes can get you a useful piece and if his price is a worse back-up only to Sabonis... keep the better player for our team to be better.
I also don't see how his value would get LOWER after being healthy and playing like normal next season. If anything, that would reaffirm teams that he's back to normal and worth the starter contract. At the end of the day, he's a damn good player on a team that needs damn good players and pushing for the playoffs. You don't just salary dump him.
Now, for a useful ender like Kleber? I'm in.