Hmm...okay, but why check and give him a free card?

Also that's a very small part of villain's range, if it's even in his range as villain might 3-bet KQss. There are many worse draws we should still charge, no?

I don't get Avaritia's argument for checking this flop when there are so many draws.

I won't speak for him and haven't counted combos but I think his point is two-fold:

1. For every spade combo he has, he has at least 3 combos and maybe 15 combos that are basically drawing dead but could improve on turn.
2. It's reasonably likely that if you get action it's from an 8. There must be about as many combos of 8x as flush draws and OESDs.

1) I'm not sure I'm understanding you here as to why this means we should check. Granted over 3/4 of villain's suited range is non-spades OTF before the shove and similar for straight draws. Are you saying give him a free card so maybe he improves and we can value bet? I guess that sort of makes sense...but there are so many nasty turn cards for us if villain likes to bluff (over half the deck) so this seems dangerous.

2) Well I've got nothing better to do so I'll estimate combos. This villain is insanely loose, calling a raise with 94ss so it's safe to assume he's on all suited connectors before the flop or very close, plus similarly valued hands. I'm left with the following non-bluffs that make any kind of sense after the flop shove, though this could be refined:

{KK-99, 77, AdAc, 8h8c, 6d6h, 6d6c, 6h6c, T9s, T7s, 97s, 75s-74s, 54s, KsQs, KsJs, QsJs, KsTs, QsTs, JsTs, Ks9s, Qs9s, Js9s, Ac8c, Kh8h, Kc8c, Qh8h, Qc8c, Jh8h, Jc8c, Th8h, Tc8c, 9h8h, 9c8c, Ks7s, Qs7s, Js7s, 8h7h, 8c7c, 8h6h, 8c6c, Ks5s, Qs5s, Js5s, Ts5s, 9s5s, 8h5h, 8c5c, 6d5d, 6h5h, 6c5c, Ac4c, Ks4s, Qs4s, Js4s, Ts4s, 9s4s, 8h4h, 8c4c, Ks3s, Qs3s, Js3s, Ts3s, 9s3s, 8h3h, 8c3c, 7s3s, 5s3s, 4s3s, Ks2s, Qs2s, Js2s, Ts2s, 9s2s, 8h2h, 8c2c, 7s2s, 5s2s, 4s2s, 3s2s, T9o, T7o, 97o, Ad8h, Ad8c, Ac8h, Kd8h, Kd8c, Kh8c, Ks8h, Ks8c, Kc8h, Qd8h, Qd8c, Qh8c, Qs8h, Qs8c, Qc8h, Jd8h, Jd8c, Jh8c, Js8h, Js8c, Jc8h, Td8h, Td8c, Th8c, Ts8h, Ts8c, Tc8h, 9d8h, 9d8c, 9h8c, 9s8h, 9s8c, 9c8h, 8h7d, 8h7s, 8h7c, 8c7d, 8c7h, 8c7s, 7d6h, 7d6c, 7h6d, 7h6c, 7s6d, 7s6h, 7s6c, 7c6d, 7c6h}

We have 59% equity against this range, by the way.

There are 66 combos of 8x and 66 assuming he's calling pre with garbage like J8o which is probably safe assumption. There are 118 combos of flush and straight draws not containing an 8. So, close to twice as many non 8x flush and straight draws vs 8x + 66. If villain favors drawing hands and folds hands like J8o-K8o there are even fewer 8x hands, but it's just an educated guess in the end.

Anyway let's say we check. Most of the time villain does not improve on the turn. Do we then check the turn again, hoping he improves on the river? And if he does, how often are we even good? We get value from when he spikes TPGK maybe, but we run into 2p+ often enough this seems very dangerous.

There's 4 other people in the pot, so you're c-betting into a multi way pot on a board that hits a calling range, where your hand looks like what it is (an overpair) and you risk getting blown off your hand when it's unlikely you can get 3 streets of value from a worse hand. In general smaller pairs aren't going to call three streets against hero was has a "solid reg" image.