If you use a cheap acrylic you will probably want to grind and start again in a couple of years bashing yourself around the head because you did not put down a better coating the first time.
After grinding off can you not afford the fast curing polyaspartic? You will have to learn how to use it, but it should be quick and ready the next day.
Most likely you will need to degrease as well after diamond grinding. Don't be fooled by the "clean" white surface after grinding. Oils that have soaked into the concrete previously will come back up and discolor the surface overnight. Removing this is important for epoxy and polyaspartic adhesion, but it is doubly important for acrylic adhesion.
Use a strong, (if they say dilute 50:1 with water use it 2:1) alkaline degreaser (water based) in the oily areas applying with a fine bristle nylon house broom and a small amount of agitation - you want the degreaser to do the work, not the broom. Vacuum after 20 mins, apply clean rinse water with same broom, vacuum again, repeat with one more rinse and vacuum. Wipe or mop up any water from under machines etc. Should be dry 1 hr later.
It will not dry at all if you do not use a good quality floor tool with the wet vac. Any residues of unrinsed degreaser will not dry properly and when rinsing if the guys step in and out of the detergent back onto the clean rinsed floor it will all have to be rinsed again. Good housekeeping is important with cleaning and coating.
If you coat with a fast cure product you will have to allow extra labor and time to do all the edges and ask the supplier for lots of advice. With quick cure you may have to mix in small batches continuously, rollers may harden if you stop for a rest, same with brushes, same with mixed batches! Choose a supplier who will give you lots of help.
