VFDs are great. I built a 10 hp rotary converter with much help from a friend to run a 600 volt 3phase lincoln MIG I bought by accident. Then I got a 600 volt drillpress/milling machine. It was a GIANT PITA starting and stopping that converter. Fine, if you are going to be using the tools for hours. The welder was the worst, plus the computer in the Lincoln never liked the fake phase.
Anyway, got rid of the welder and drill press. Still keep the converter, just in case. It also draws an insane number of amps on startup which is probably not allowed by the utility.
Some guy was here this week buying some old equipment from me and told me how the Utility Raped him in all manner of charges for 3 phase power, so he runs generators.