I’m pretty terrible with a paint brush and have been practicing veneering. I just tried a foam 4” roller and it worked well... so far. I wonder if these are one time use or if they would “flake” off? In all my searching no one recommends this method. Menards doesn’t have glue rollers... so I’m working with what I got Is it okay for me to use a foam roller to spread contact cement for veneering?
You can certainly use a roller to apply contact cement, but often this is done using a solid roller (usually a hard rubbery material of some kind), not a foam or short-nap roller because of the difficulty or impossibility of removing the residue of the adhesive from a paint roller.
Note there are various types of contact cement however, some are waterbased so presumably can be easily cleaned from paint rollers.
Alternate application tool
You can apply contact cements using spreaders, at the most basic this can be an old bank card or credit card, others use plastic wallpaper spreaders (used for working out bubbles), putty knives (with the corners rounded off) and even improvised tools made from the plastic laminate they're using the contact adhesive to stick down.