You can print standing up on a standard ender3, on a 45-ish degree angle- when you put into Cura and move around, the image style will change when it will fit on plate.
…. Make sure your use a brim of decent perimeter around edges 10 is a good number. It takes a while to print, and can distort without a reasonable surface area on plate. A raft will also work if you have the height available.
Your base looks slightly uneven, but will probably be ok, if both are exactly the same.
Enjoy your build.!
How has your printing gone overall? Ryan did say in docs, that you should print in the same orientation as he has made, or saved the files.
That is how I did mine, and apart from having to be printing my x carriage 4 times because of various failures, everything else is good.
One tip, after screwing my XY rails to YZ plates, the screws don’t seem to hold well, so when I have cut my plates, i will drill and assemble with screws and nyloc nuts, to hold XY rails to plates .
Trust but verify. I get this is older post, but I am just getting ready to use my LR2 to cut my LR3 XY plate. Any chance you could do a similar measurement on the other plate (XY plate) so i can be sure my CAD has this dialed in before I go to cut? I don’t trust what I see at the first.