I picked up a low profile gas block that slips on and has 2 screws in the bottom to secure it.

I'm used to sight towers being a press fit, but this feels like it is a "RC3: Precision Running Fit" (https://en.wikipedia.org/wiki/Engineering_fit)

Is it tight enough?

Tighten the two set screws if you want it tighter.

Thanks dude!
I'm used to the towers that seem to blow out a lot of gas in spite of being much tighter than this thing.

snug it down. It'll be fine.

That's an "automatic over-pressure compensation" feature. You should have been made to pay extra for it.

You never know until you put one on due to varying tolerances. I've got some that slid on with little to no effort and some that had to be tapped on with oil and a nylon punch. All of them work fine though.