On the flop, without backup really I decided to check 3-way and go for a c/r if IP bet. That way I can dramatically lower the SPR and deny quite a bit of equity. What I'm unsure about with the line I took if its better to c/r pot to $27.50 or if my sizing is alright to $21? Am I giving too good of a price to call for hands like JT9x?

I think you should be betting here since your OPPs are weak and most likely passive.
As played OTT I think we have to check/fold if he pots it.

all in

We have 24% to improve to a better hand. We are getting about the right odds 26% to call a shove on the turn.
Villain will probably bet all his straights and x-back sets. If we shove ourselves we could get paid from these sets.

Other considerations could be:
Our UTG Opening Range shouldn't contain that much sets, so Villain could be more intended to 3bet his Sets on the flop. Most players Push or fold smaller sets when get x-raised. Therefor villain shouldn't have any Sets in his rage. If this is truth than he may, in rare cases has some floats in his range and will bet as bluff on the turn. Or what could be possible too - he x-back all non-nut-straights and we get a free card or even showdown. Also nut so likely but than we could go for x/c.

I think everything but folding will be +ev. I would tent to x/c on the turn when he x-behind on the turn, than x/f the river.

By the way, if we do not bluff on the flop that often we should pot here, imo.

Grunching.

On the flop, without backup really I decided to check 3-way and go for
a c/r if IP bet.

I really, really don't like this.

This flop is somewhat dry, but not completely. (By the way: you have backdoor hearts; that isn't nothing.) You know this because you got confused on the turn, as the nuts changed.

Here's the main thing: you can see three queens between your hole cards and the flop.

What do you think BTN is going to be betting? Top two? Top and bottom? Super unlikely; there are only four queens in the deck.

Going for a x/r as PFR here is extremely wishful thinking, and you're really lucky that BTN bet (and even more so that BB called said bet).

Not only is going for a x/r here wishful thinking, but your opponents' highest-equity continues on this flop (straight draws) are completely unblocked and you don't want to be giving free cards to them! Against JT9 you have less than 60% equity (HU); don't get cute!

As played, the SPR is so low on the turn that I don't think it matters a ton what you do as long as you don't check/fold.

There's a discussion to be had re: the turn, but I just think it's extremely important to not be checking this flop, even if it actually honestly worked out okay.

100% bet on the flop, it’s multiway and with top set with a lot of bad turn cards you never want to give away free cards.
Fortunate that you got to c/r but I would advise for full pot, there is nothing he calls there against this sizing and folds to a pot raise.
Maybe 86 if he bet that, but given it’s a rec I see him probably calling even this, especially if he has backdoor draws, not charging your weak opponent with your value hands is a very big leak, they don’t think about sizings especially in these kind of spots and you just go for straight value here.
On the turn, the spr is so low that you can’t fold your hand, just go to propokertools and look at your equity versus several straights, and keep in mind he doesn’t even always have a straight, but also hands you have crushed.

gl at the tables