Consider the RMR on an angle mount. It works, they have a 4MOA red dot variant, and it’s far more low-profile than the H1. Either will work well in that application; you’ll pay close to the same with either one, durability on both is very good (though the H1 has more institutional history in that regard), dot size close enough as makes no difference good it’s a bit of a coin-toss.
Not a fan of top-mounted mini-RDSs. Tired of seeing them getting ripped off the top, which bungs up both optics. It’s still a popular setup, however.
I have a FastFire 2, can’t recommend it. I relegated it to a shotgun due to #1 short battery life and #2 durability is questionable even with the improved protection of the metal optic protector/riser. I would not want to beat this sight around.
The Insight MRDS are VERY nice and worth considering. The Aimpoint T1s are still my favorites overall due to quality of construction and battery life.