Mike
Yes, Pi offers a wealth of ways to create masks, Snip Mask is one of many. Each mask has its own application areas and each user has his own preferences.
Of course I also use RangeSelection, but the tool affects the whole picture. I wanted to create a selective mask. But to my knowledge there is none, with which you can really create any kind of shapes. And sure, you can apply RangeSelection to the snip mask with values as you like.
Gerhard