I'm not sure if it was working before, as I didn't try it (dummy me), but I just tried this since there's a new patch out today...
Create custom arena.
Go to arena tables and select the tables you want.
Click upload to host.
It will cycle through every plane type and every field.
When it's done, all your tables are set - variables, fields and planes.
I had to re-upload the MOTD, but at least I didn't have to hand-pick every plane at every field.