Alleycat, I agree- if his pistols don't "folow" most people would give their eye-teeth for them.
But he just has no option as you say without training.
I recently had a Caspian frame that I worked on for four days (part time) till I got a 5# trigger. That thing would go together with a 3# pull and with use would "grow" to 6#! Never saw anything else do it! I finally put a behlert hammer and a nice long sear (dressed) and got a good crisp 5# pull, very crisp. Couldn't understand it only it must have been the distance between the hammer and sear holes! It was factory drilled and tapped on the dust cover for a Caspian mount and I got it for some milling work. I think it was a "factory second" frame possibly - it's fine now and I carry it!
The only thing I can think of where he could do almost no harm would be to increase the bend inward on the sear/disconnector spring - hence the trigger bow. Also, increasing the inward bend on any of the two left springs would likewise increase trigger pull but I'm like you, I wouldn't say for anyone not familiar to try it.