Wolverine's primer, BondTite 1101, is compatible with most epoxies out there, but with any coating it's difficult to say with 100% certainty that it's compatible with an existing coating.
If the current coating is adhering well with no lifting, you should be okay. But, sometimes a coating that's sticking well can develop issues when it's over coated. Considering the resources it takes to install a top notch floor system, it's really best to remove the current coating so you can start with a clean slate and guaranty your new floor is as durable and good looking as possible.
The last floor I helped with needed to have an existing coating removed first. The floor was about 400 ft2 and it only took about 3 hours to grind it clean with a dual head Edco grinder, and it was an older floor with a very uneven surface. The toughest part was loading and unloading the grinder - that puppy was heavy!
If you do opt to just rough up the current coating, wipe it down with some denatured alcohol right before applying the new epoxy.
Our Tech Note about re-coating is attached. It addresses using a Wolverine coatings over existing Wolverine products, but the same steps would be taken with most epoxies when going over other epoxies, just keep in mind that due to the thousands of possible permutations of different products and combos, it simply isn't possible to test them all, so results and compatibility can't be guaranteed. Best to check with your supplier for specific details.
