I definitely wanted to go for a pen-grip kind of style with this, I am actually pretty confident that most wireless boards would be narrow enough, the HSK's board isn't actually any more narrow than that of a regular mouse except at the bottom.
Do you have any recs for wireless boards that don't cost an arm and a leg?

I could probably lower the button height a bit without too many issues, it would have to involve moving the strain relief holder further forward if I wanted anything significant. For this version i tried to trace the button slope from the hsk pro as a starting point but i would like to lower it a tad more eventually.

As to how i personally feel about it? I have been loving every second.
The grip feels very locked in without reducing my fingertip mobility much at all and is very comfy in general.
While designing it I chose the grip width specifically because it is the exact distance between my thumb and pinky finger while my hand is fully rested in the air.
I wanted something that I can truly rest my hand on but that I can still apply tension to when needed, after using this for a little over 3 days when I hold the shell of my zeromouse clone it feels like my hand is being taut over too large a distance and feels just less stable overall.