The local casino has 4/8 LHE with a $2 BB and $1 SB . Preflop betting is still in increments of $4 but you only pay $2 for the BB if you don't want to complete.

Rake is 10% up to $5. The game is 9 seated and always plays tight passive or loose passive.
The players are more interested in chasing the jackpot and promotions than playing good poker.

Is this game much more beatable than 4/8 with full blinds? The edges are pretty small in small stakes LHE so the few dollars per round should add up.

Changes pre as attacking the blinds is less profitable. It's hard to know whether 48ers adjust. They probably do not tighten up enough.

these games tend to suck and attract huge nuts. ventian tride 15-30 with like 5-5 blinds and was awful

Yep.
Is the rake 5+1 or 4+1? Seems like if there are BBJP and promotions, there's extra rake.
They're going to play super nitty in a game with tiny blinds? That's a good start at good poker. It could be that they're terrible at poker, but accidentally, they're playing correctly preflop.
The thing that adds up is the lack of $ in the pot. You're trying to beat a pretty big rake. One way that works is if people play loose/badly and the pots are so large that the rake cap makes the effective rake a smaller % of the pot.

Another way it could work would be that these guys play terrible poker, like throwing in a few $4 calls and then making really bad folds later? You need them to be really bad to beat $5 or $6 rake at 4/8. The rake drop is an unstoppable opponent.