You didn't really go into detail on Turn & river strategies for 3! pots. Are they mostly the same as SRP? Or are there differences because of the lower SPR & range polarization?

They are mainly different because of the lower SPR.
I'm planning on doing a future video on 3bet pots, I can give some ideas here.
In general 3bet pots are more aggressive because off the lower SPR. In standard SRP pots you will see the more polarized player betting, the other player checking. Due to low SPR you will sometimes see the other player betting, just to deny equity.
The same holds true when facing bets, you will see more raises (All-in) to deny equity.

In practice this isn't being done often enough (the raises). So you get to bluff more often than GTO would suggest. My advice would be:
When SPR is <2, bluff a lot on turns (with high cards). You will not get raised often enough. Any high card on the river allows then for value bet or a very good bluff opportunity, which makes it worth it.

As far as bluff selection (in theory) works: Use this sentence "How much would I hate bet-folding this hand?". Don't select bluffs with good equity that you have to fold when you get raised. If you have KQ on JT74ss then it's better to use KQo and not KQss.

As far as calling 3!s- do you generally not want to do at stakes as low as 25nl? I'd imagine you want to overfold OOP and can consider calling IP with hands like 88, 99, TT and suited broadways.

The issue is that population isn't 3betting often enough. Your continue range will be up against a too strong range, so it's not worth it to continue with some weaker hands. Pocket pairs can be fine if you get great (implied) odds for it. Suited broadways I'd be more cautious with.

I notice a lot that pio likes to barrel turned draws a lot more than our draws that we flop

Draws on turn are barreled because they have some equity. And generally SPR is big enough. You can't barrel them when they miss because they block your opponents folding range. Your opponent will call flop with backdoors and fold those on the turn when the backdoor misses.

I also notice that in deeper spr spots as ip we don't barrel a lot with a block size. It seems we are almost always more polar than oop.

Do you barrel often with blocksize on turns? I generally don't. Because when we bet flop and our opponent just calls we end up with the stronger range. As we have all the 2P+, top pair strong kicker. When your opponent doesn't raise he is saying he doesn't have these type of hands. So you generally end up with a more polar range on the turn. Depends on the turn card of course but generally that's the case.

For flop textures I recommend using the idea of "Relative amount of marginal hands with incentive to bet" idea. I talk about it in this video https://www.runitonce.com/poker-training/videos/shaun-pauwels-theory-video-fighting-simplification/

Agreed. I'm playing 10nl and 10z now, getting my beak wet again, and seeing more play and explains from Shaun would be quite welcomed. These are great videos for today's games.