The O-rings on the spout of our American Standard kitchen faucet wore out again; having described that repair many times, there’s no need to say much more about it. I didn’t want to get into this repair while thinking about the hot limit problem, but I did check to make sure the box under the sink had some O-ring replacement kits.
A bench vise with soft jaws holds the spout while you remove the escutcheon ring retainer:

Basically, just tap around the ring with a long drift punch and it’ll eventually fall out onto the reasonably clean rag below it.
The interior of the spout before cleaning shows why you should never look into your plumbing:

After a few hours in a white vinegar bath and a few minutes of scrubbing with a ScotchBrite pad:

Another view:

Obviously, you could do better, but it’s hard to get excited about the last few nodules. For whatever it’s worth, the nodules grow despite our water softener; I have no clue what’s going on in there.
A few wipes of silicone grease, reassemble in reverse order, apply a firm shove, and it’s leakless again. For a while, anyhow.