Mark, you need three points to level something; such as an accurate balance or my commercial laser level. All the commercial granite plates are flat by design but not necessarily level! They all have a metal frame with four legs, level is not a requirement. I do agree the fifth leg is a royal pain and agree with Brian it will just pull the other legs off the floor. I considered bolting it to a concrete plate with a spacer in the middle to provide leverage as an attempt to flatten it.
I may have solved my problem however. It may get sold to a local pharmacy as a balance table for their new compounding room. The mass of the granite counteracts room vibrations for accurate weighing. The fifth leg is gone and the drawer back! Money raised should cover a Kijiji listed commercial granite plate!
You can do a lot with very little! You can do a little more with a lot!