Yea I saw that note that Zoinkity had left about the pointers to team plays and what not. I seem to remember this address:
0xDAE70 80336E20 team offensive playlists; 0x1B ea.
had some very odd looking code.. so I may have been unknowingly looking at the actual play data.
The line of scrimmage going across the y-axis is at 0A. No x-axis for it, as it goes straight across the whole field.
Here are the hex values for the red exclusion box.
I think the play editor does indeed snap to a grid, in the sense that each x,y interval is 01 apart from its nearest neighbor. I think we could create the field to have the same total amount of x,y values as the playbook editor. It's a 26 wide x 42 tall field, so as long as the editor has the same amount of intervals as this, we can easily correlate them to the hex values. Actually, if we wanted, we could have the y-axis longer if we wanted, as you can actually increase this value beyond what the in-game editor allows you to do. So if you wanted to make a "da bomb" or "hail mary" type play where the WRs keep going, you could do so.
Just checked if we can add multiple actions at the various nodes - yes you can! I edited my play so that WR1 and WR2 have about 6 spins each and tested the play. They did all the actions I specified! So it looks like we can remove that limit for the various actions if we want to. Here's a screen shot of the editor showing all the spins in a row.