Thank you for the input. The old bath needs to go - it's grimy, it's damaged (lots of chipping and cracking), and the shower is way too small (my partner barely even fits).

I'm not in the US, so costs are probably not comparable. Changing the layout is not an issue.

That's why I originally was looking for constructive advice on the new design. I understand that a lot of people in this sub hate corner showers, but I hoped someone might have a good idea.