Is that 'boundary' on the outside of the tray? I.e. you would be stepping over that to enter the tray?
Yes. I actually went and made a specific thread on this issue here:
https://www.diynot.com/diy/threads/constructing-a-shower-curb.488359/
Is that 'boundary' on the outside of the tray? I.e. you would be stepping over that to enter the tray?