I get it that some people have issues with high-intensity thumbpulling with chin-tucks, but isn't that simply because, they should start with lower intensity and only after some time the body will adapt to higher intensity?
The rationale is similar to reviv mouthguard. A person who's super recessed shouldn't immediately try to wear reviv XL for 12 hours a day, but should start with wearing a smaller mouthguard for less time.
Personally, I've been doing high-intesity thumbpulling with chin-tucks once a day 4 sets for each third of the palatte for 4 months now and I've gotten massive results. Also, it takes me literally 5 minutes a day, so that's great stuff.