How much CDR should one optimally get on champs with reset?

You could if you want through masteries, but it's not really needed. For example, what would you even build on Kat that has CDR? Morello/Athenes mana is wasted, so will of the ancients?

Same goes for Yi. Highlander is a fairly non restrictive ult, only thing youd really need CDR would be for his W.

0 lol

Why else do you have resets

The only thing you would build on Kat is CDR boots, which means she has to sacrifice magic pen for it

Yi's ult reduces the current cooldown of his basic abilities for a kill/assist

Trist's only reset is your jump so you don't need CDR for it

Jinx's doesn't need CDR either

Akali's ult gets a charge on a kill and has a relatively short cooldown

The only reset champ I can think of that does benefit from having a bit of CDR is . Everyone else either scales better with AS, already have short enough cooldowns or simply shouldn't be using more than one rotation before the fight is done.

No CDR on kat Probably a ghostblade on yi but thats standard stuff

You don't need CDR on resets. For Yi just build AS and your Q will be up stupid fast. Kat doesn't need it at all.

Generally, reset champs don't build CDR as a direct stat. They may pick it up as a side effect of the actual stat they want though (like Yi with Ghostblade). However, I do build CDR boots on Kat, and if you really wanted to, you could grab WoTA as well. But other than that, no, you don't need CDR

If a champion has resets, CDR isn't exactly a stat they're going to invest in. Maybe the obligatory 5% from Masteries and like 10% from some item in their build path but otherwise hardly a stat that's actively focused on.