you want to change the cuddle Interval. The lower the number the quicker the imprint.
Ok awesome. How do you increase the % for each imprint?
You can't, unfortunately. The imprint % per cuddle is calculated from a hardcoded formula that compares total maturation time to the cuddle interval timer. If you care, the formula is: 100/(floor(M/C)) = Imprint%
M is the total maturation time and C is the time between cuddles.
The easiest way to do it without mods is to set your cuddle interval to the opposite of your maturation multiplier. With a maturation speed of 100 you'd want to set it to 1/100, or 0.01.
With those settings, you're essentially speeding the whole process up by 100x from official settings. You'll get the same number of cuddles and the same imprint percent per cuddle, it will just happen faster. You'll have to keep an eye on them the whole time they're maturing, as they'll want a cuddle every 4.8 minutes.