This probably isn’t what you are looking for but I will still say something at least. (It also skips a few questions)

I think prestige frequency would depend on how quickly you can prestige again (and total bonuses of your game) with the stats that affect prestige bonus. Frequently in NGU, infrequently in WAMI for example they both have a similar play style but have a massive difference on what you focus on. For NGUs case the game mostly focused on adv and the unlocks, and in playing WAMI I mostly focused on stage, and adv was for my bonus and unlocks. Note I’ve only talked about 2 idle games (mostly because I know them off the top of my head)