true i was talking more generally. you could still 5b and essentially leverage your whole stack. or is that lol bad to 5b to ~1300 after BTN 4b to what I would assume is 2.75x-3x so roughly 465, and fold to a ship?

Fold or 4b. Which one depends on V's tendencies. His 3-bet range. How much of it is bluffs. How much of his value range will your 4b fold out? Can he 5-bet bluff? What's your image? What's his? What's your history when you're attacking his blinds? How often have you attacked his blinds from LP? How often did he defend and how? I think this stuff (history, image, metagame, etc) comes into play here.

prob a good idea to not get into preflop betting wars against "solid players". they spazz too much and end up handing you their stack too often (if you have a real hand pre of course)

Prob folding, rarely calling. 4 betting sometimes based on history, dynamics, frequencies, etc, not necessarily as a fixed part of my 4 betting range.

If your 4b 100% here it has to be a leak
You should be 4b bluffing some % of the time here thou esp w villains w history
Calling is also totally fine

This. Surprised people are definitively advocating one specific option with the info provided. We need much more info;

How bad is CO and whats his postflop tendencies? As this will affect his 3b range esp if he's depolarised.

Do you have any read on his general postflop tendencies in 3b pt; is he over aggro? Does he like to pot control/give free cards? Is he very sticky? Does he cb 1 give up too much?

Info on his oop aggression in hu pt gen. Postflop sizing tendencies. Have you 4b much and gone to sd in pots he's witnessed recently?

Then mental/macro factors like general history, your in session image, his in session image, is he winning/losing? Are you winning/losing? What stage of the session is it?

If villain is unlikely to flat your 4bet, I'd rather 4bet/fold a junkier Ax hand. Against someone who hoods 4bets, call or 4bet is fine.

Haven't ever got to showdown before. Usually just fold a lot to his 3b's, and haven't had too much deep stack experience. The limping CO villain has around $600 behind. Prob pays off a bit too lightly. Comes into pots with all kind of garbage hands. If I was the SB regular, what hands would I want to be 3-betting in his shoes and which ones would I want to be flatting?

He is going to be 3betting you with anything from Ax suited, AQo, AJ, A10o, KJ, KQ, K10, JJ+, maybe even as light (since he knows you fold a lot to his 3bets) as JQ.

If we 4bet/fold, because we know he is light, he is probably not flatting oop, so he's either folding or 5betting. However with A4s and not knowing what he will do to our 4bet it would suck to have to fold to a 5bet so I am leaning towards folding and waiting for the next time till we get something like 1010 then we can 4bet/jam it (unless we're too deep).

I think this is pretty interesting because everyone thinks something different and I don't think anyone is wrong, it is really a function of the playing style you are comfortable with and to a lesser extent what your opponent won't expect. Personally I would never consider folding and probably just flat 80% or so.
One of the hardest improvents for me to make has been to consistently consider all options instead of just fold/call or raise/call.

No way in hell calling is "lighting money on fire". If it's a mistake it's a small one.

Also DGAF nailed it everyone likes to talk about how aggressive they are but when they get QQ/AK in this spot they're flatting the 3b not 4betting.

Calling or 4betting are both viable options and mostly depend on V's tendencies and hero's postflop abilities or lack thereof. For example, if V plays weak tight postflop hero can float and take it away on the turn which probably makes flatting the better option. On the flip side, if V has a lot of bluffs in his range and would also fold JJ/AK to a 4bet because of hero's image or whatever reason then 4betting is probably more profitable.