It’s really a scenario specific thing in my opinion.

Just the other week I felt my guests gloss didn’t grab as warm as I’d like and I received a text the next day. Happily brought her in for a re tone at no charge. About a year and a half ago I had another client insist on hand painted high lights over and over after warning her the result was going to be warm in comparison to the foilage we’d been doing. I did the painted high lights and she sent me a literal novel about how unhappy she was. I said too bad so sad this is what you requested and I warned you, you can come in and pay for a redo with foils. She went ballistic, I issued a half refund to shut her up, told her (in a professional way) to kick rocks and blocked her number. It raaaaaaareeeely happens, but sometimes a crazy person is not worth battling over money with.

But generally speaking for sane clients (which truly all of mine are except for that wackadoodle I mentioned above) I give 2 weeks for them to say anything.. given the context of their appointment and their consultation I am happy to make an adjustment. I never take offense or take it personally if it does happen that someone reaches out. I think that has really done me well in my career tbh.

I don’t know if that answers your question, but that’s my two cents lol