What is the typical waiting time for a Non-O visa extension under consideration in Thailand?

You SURE you're stamped with an under consideration that that expires on the 12th of July?

I ask because that's a Saturday and as a rule they don't give under consideration stamps that expire on days immigration offices are closed

If I was to guess I'd say you applied based on marriage / raising thai child and got a 30 day under consideration stamp that was ADDED to the expiration date of your Non-O 90 day stamp

Which from when the U.C stamp runs out seems like it might have expired around the 12th of June) 😉 <- they add the 30 days under consideration to the end of that stamp

BUT

I'm just guessing