@RiotDemon – I’m not sure why astigmatism would be a significant negative for using binocs. Astigmatism just means that you don’t need the same level of correction in each direction one particular eye is collecting light from. Astigmatism goes by each eye (although you could have some in both) so I am also unsure what advantage a monocular would have, other than one would use it on the unaffected/ less affected eye?
In my line of work (retired now), I did a lot of microscope work using a binocular head, usually without my corrective lenses on. I have a pronounced astigmatism in my left eye, but never had an issue even after hours of use (much more than a binoc would be used outdoors). I think the brain does a very good job of filtering out anything that is unclear in one eye if the other eye sees it well. That is the principle behind “mono-vision” (one eye corrected for near vision, the other for far) that many contact lens wearers use to combat age-related near focus problems.
A separate issue is if the binoc has provision for a diopter correction (one eye needing more or less of a correction than the other) on one of the oculars. I half wonder if that is what SoftAsFur may have been thinking about (as the lack of that would be a problem if your eyes need correction)? This pair does have that (see the 4th photo, with the + and - signs under the knurled ring on the right eyepiece).
Lastly, if you wear glasses (or contacts) that have an astigmatism correction, and also use them with the binocs, there should be no problem whatsoever with either the astigmatism (or diopter) correction issues, as the corrections built into your glasses will eliminate them.
I think crossover binoculars should let the light from the left objective come out of the right eyepiece and light from the right objective come out of the left eyepiece. I think that would totally mess with your brain’s sense of depth perception, making nearer things seem farther and vice versa. Probably make you throw up. Good thing they’re waterproof.