Results like these is why I haven't attempted a pair of jeans since 1982!
Steaming and a Clapper couldn't hurt. Perhaps even a slightly less bulky new needle? (That sounds counter-intuitive, but your machines may not like the heavier needles?)The 201 was developed for dressmaking of lighter weight fabrics. Do you have access to a 15? They were meant to be useful "on the farm". I haven't used mine yet, but I'm expecting it to handle this stuff.
The good news is, if you look at high end jeans ($1400 - $1500 per pair) your pockets are stellar! Unfortunately, anyone that knows me will know I've not wrapped my 62 year old bum in thousand dollar jeans!
If it were me, I'd carefully fix the skipped stitches by hand and look for a 15 or some other machine proven to handle denim before I attempted another pair.
Maybe someone else will have a better idea, but I think it's the machines with the problem - and not the operator - in this instance.