Great questions.
I did test the eye relief and I found the two scopes to be similar. Swarovski advertises 20mm eye relief, which is pretty long for scopes like these. The Kowa is only advertised as having "generous" eye relief. In practical use they are very similar in eye relief. Not difficult to get a full FOV without glasses, and suitable with glasses, but not anywhere as forgiving as a folded light path scope like a Leupold Gold Ring.
If you have used the full size Swaro ATX/STX series scopes and the full size Prominar Kowa scopes, you will know what to expect with eye relief, as the little scopes are just like the big ones in that regard.
The mounting foot on the Swaro was not a problem for me, as I used a Peak Design Arca compatible plate which doesn't need much space. I think most hunters will find it suitable.