I've done a few and always painted them with 1-Shot.
This is done during the refinishing process.
Floor guy comes back the next day and applies a few coats of Poly...
Last one I did was about 5 years ago for an elementary school.
It was the alphabet the length of the gym floor in 12 in. uppercase letters on one side and lowercase on the other side.
There was also some circular panels, striping and such that the floor guy was handling.
I was curious and asked him how he was going to go about it and he said he would tape everything out and the Boy Scouts would come in and paint it for free to earn credits, badges or something like...
I was surprised and when I came in after they painted it looked pretty nice; no spilt paint between the planks, and no fingerprints or footprints around the floor...