Just call down most runnouts and depending on sizing. Villain is a weaker player most likely given stack size so can show up with all sorts with this line. Also think i would prefer a smaller size on this flop multiway

Flop - I believe when we see cold-calls in 3bet pots and we see the flop multi-way we should be looking to apply a lot of pressure by betting really small. Force them into a corner for making the mistake of cold-calling the 3bet. I would choose a size around 20-30% pot on this board. $0.65-0.75 c-bet.

Turn - When villain leads I believe we need to be reducing the EV of him splitting his range, on a board where he should not be splitting his range, by raising him very aggressively. This hand unblocks almost every single draw and fits perfectly into a shoving range. If you just flat here you allow him to realize equity cheaply on a board that favors your range which I am almost positive is a big mistake.

Yeah just shove, the opponent is clearly fishy so there's a lot of value and protection to be had. Calling is another option, but I would prefer that on a more dry texture.