Yeah, I think Hex-A-Gone is good enough that it can absolutely stand as its own game. There's a reason why it and Slime Climb are so frequently cited as the best minigames.
Also, the chaos created by other players' differing strategies and having to account for that in your own gameplay saves it from feeling repetitive, IMO.
Absolutely. I thought I'd perhaps not enjoy the Thin Ice Trials so much but actually, it's made me like Thin Ice more, as the first round is the chaos that I kind of needed with that final! And pausing to look at the different strategies (or often lack thereof) is really fun.
And I've been pretty poor at pacing myself with Thin Ice historically (treating it more like Hex which is a mistake lol) and it's helping me improve a lot.