Last session we had a particularly convoluted climbing challenge. There was a 50' tall cliff and we wanted to scale it to get to cut out a considerable section of the road. The DM had each party member make an Athletics check per 10' section, with a Dex check on failure to avoid slipping/injury. We were using ropes to mitigate the circumstances, but with 4 party members this ended up taking over an hour of RL time. I'm of the opinion this could have better been handled with just a few skill checks per character instead of well over 20 rolls per person.
I'd like to talk to the DM about this privately, to avoid needless mechanic slogs in the future, but I'm not exactly sure the best way to approach this would be.
I'd especially appreciate suggestions for general phrasing/approach here. I've been gaming possibly longer than my DM has been alive, and I don't want to come off as "I know better than you" or that I think he's a bad DM for engaging the mechanics a little excessively.