GAry,
You pays your money and takes your chances. The safe way is to use the thinner formulated for the paint you are using. You know that will work. If you deviate from that, it may work fabulously (I think Randy Ryan uses thinner from the local hardware store of something), or you could create a problem for yourself. Hey, you did the right thing and did a test panel. I would expect that as long as you use whatever brand of dope you used for that test panel, it will probably
be fine. Probably.
Like I said, you pays your money....