I used mine at f 32 and a little closer then infinity with much succes, but you can only shift about 2 cm then the corners start to get dark!
So I do not recomand it as a full 8x10 lens, but in emercency it covers the format. the corners will then not be at the sharpness what Rodenstock would accept, but in my picture it was only the air anyway!
The 360mm APO Ronar is a fully usefull 8x10 inch lens!
I've used this lens on both 45 & 310 for decades and it's served me very well. It's my favourite for 810, small, light and of excellent image quality. Sure it doesn't offer any signifcant movement ability but that's a job for another lens.
Can't speak of the sharpness in the corners. All of my subjects tend towards the centre of the frame. I put clouds and blank pavement in the corners.
If you get the chance, go for it. It's a gem.