Don't do this! If you want sign to fail within short time than go ahead. We use semigloss or gloss latex, if rolled with foam or sprayed it will hold vinyl and outlast enamels.
Say what you will, but after making many signs over 40 some years.... the only ones that ever fail have been my competitors..... who usually choose the cheap latex paints, cause it's easier, faster and cheaper.
There's a recipe for success.
While it's true if you use a high end high gloss latex, you can make it work, but it will never compare to an oil-based paint. In my opinion, it's like using margarine instead of butter. It's just so-o-o-o-o much better. Do you use artificial bacon bits on your salad, too ?? Anyone for tofu meatloaf ??
Seriously, use the latex if you like, but why do you think people painting the outside of their houses have to repaint every few years after the paint fatigues and looks like chalk ?? Compare that to years ago using good oil-based paints [
with lead] lasted for 20 years and more. Even without the lead, the oil-based is a far better choice.
We have signs out there for over 20 years and it's the vinyl that gives out.... not the board or the paint.