what do you mean, I don't understand? so you used it and cant get it off, or are planning to use it and worried it wont come off? I recently painted parts of my car flat black, used hot rod flats boulevard black flat
It's just a very light wax. Use wax and grease remover before you sand the existing paint and you should be OK.
I used to work at a Haley shop. We used it to keep the bikes shiny. It won't hurt the paint, but you might end up with more shine on your flat black than you want. If you're concerned about silicone contamination and painting over the flat, know that it does have silicone oils. Ingredients here: http://www.whatsinsidescjohnson.com/en-us/products-by-brand/pledge/favor-furniture-polish.aspx
It has already been applied - got the recommendation from the HAMB. It looks great (it does have a shine after application) but there were some posts here that claimed getting it off for repaint was a nightmare.
You wash it enough with real wax and grease remover and you should be fine. Do you use any tire shine?