I pay a lot more for draws against maniacs because I assume the implied odds are there. But that’s probably an overall benefit to them in the long run. Sure it works sometimes, but they want me to pay extra for draws.

I know there’s a limit to the question, but I’ll probably pay 20% more than I would against most players for draws against maniacs when I feel like there’s a good amount behind. Is this a bigger leak than I’ve always assumed?

This is a fun question. Implied odds are very sensitive; if they're gonna start stacking off 100bb deep with all their top pair good kicker+ hands and a bunch of bluffs on any 3-flush board then the value of your flush draws skyrocket. But if they're two-barreling thin value and giving up a lot when the flush card arrives then your implied odds probably aren't great.

How much extra you should be willing to pay for those implied odds largely comes down to how much is behind after calling, and the price of a call relative to the pot.

You may want to check out Statmanhal's blogs on implied odds and the relevant calculators.

Drawing to nut flushes will always be better than drawing to smaller flushes but I imagine it’s even better vs a maniac because they play so much low suited junk that u can over flush them and have massive implied odds.

Same concept for drawing to the nut straight like having KT on J98

The simplest way to think about it IMO is using basic pot odds BUT adding the [percent chance your opponent calls] multiplied by [your river bet] to the current size of the pot since that's basically what you win when you call.

Example: Starting with the most basic pots odds scenario lets say my opponent bets 100 into 100 on the turn and I have a draw, I need to win 33% of the time assuming no more money goes in (calling 100 to win 200). But let's look at the same scenario and add in that I think he will "pay off" on the river 75% of the time vs. a value bet of 200, then I only need 22% since I'm essentially calling 100 to win 350.

Of course this is only a simplistic model to be used as a starting point, there are complications in real poker where if you hit your draw you might still lose vs. parts of his range (e.g., you hit flush he hits boat), or your nut flush draw can win with ace high even if you miss, etc.