Trying to change the hand guard without the delta ring tool is a giant pain and you can mar your rifle.
I've changed or removed standard AR hand guards many, many hundreds of times and have never used nor wished I had a delta ring tool. It's not that difficult to do, and I've never had problems with plastic hand guards marring my rifles. How is it even possible to mar a metal rifle with a plastic MOE hand guard?
OP, I'd not worry about damaging your delta ring removing your hand guard. That's what it's designed for, and you're not going to wear it out taking the hand guards on and off even regularly. Worst case scenario, if you could find a way to wear out your delta ring, a brand new assmebly will cost you $10 and take less than 15 minutes to install.