in my opinion thumbpulling has 2 phases:
Suture activation: when you do it enough time for your sutures to activate. this takes about a month or so, but depends on your age. if you are young like 17 yo when i started doing this, it will take maybe weeks (the sutures are still going to expand but very slightly)
Suture expansion: when sutures are already active the palate becomes very elastic, meaning you can expand it easily, the downturn is that it also comes back to the original place overtime, meaning that you have to do it oftenly enough for ur sutures to fuse in the expanded position,
In escence, you have to do it oftenly, but its not necessary doing it once an hour. i do it 6-8 times a day doing in total about 5 minutes of each excersice in a day.
keep in mind: if you stop doing thumbpulling for a week you will lose a lot of progress, but as the tissue has certain memory, getting that progress back will be 3x faster, this is like building muscle and then losing it, you will be able to build muscle way faster (speaking in personal experience)