I had a Formica countertop that originally had an edge with a raised bar. I removed the Formica and the raised bar - it was made up of a stack of 2x4s that I removed - the last 2x4 that I left was about 3/4" higher than the cabinet tops so I laid down 3/4" plywood. This worked well but I noticed on one side the 2x4 is a little out of level so the entire surface isn't perfectly flat.
Is it possible to use something like self leveling floor patch compound to try to smooth out the surface for the quartz or should I just let the countertop guys use shims?