Phase converter going in

You are out of my league, (I think I said that wrong, LOL) HP wise, on this one. But I agree with the others as to capacity concerns. All phase converters that are motor driven are quite inefficient. There is a LOT of losses.

Also, high HP 3 phase motors have very different starting loads than do single phase.

One thing I would investigate on the compressor, is using a smaller motor pulley to slow it down some. I would also investigate different unloader options, to maybe allow it to "soft start" under no compression, a way to allow it to spin up to full RPM and get running, then close the unloader. I am not exactly sure how you would do this. Perhaps a solenoid operated unloader, driven by a time delay relay.

You may be aware, that the head operates at VERY high temps, so any unloader "rigs" you need to keep that in mind.

This chart here suggests that a 10hp SINGLE phase motor draws about 50A full load at 230V single phase

https://www.elliottelectric.com/Sta...calTables/Amperes_Single_Phase_Alternate.aspx
You will be (if anything) WORSE than that because of converter losses. And remember, that 3 phase motor plate loads are are per phase, aka you have 3 of them. But 3 phase is not 180 or in phase. Three phase is 1/3 of a wave out of phase with each succeeding wave, so this skews the load ratings. But with your proposal you are essentially pulling single phase loading + the inefficiency of whatever converter you have going. In other words, and this is a guess, you need to go by a 25hp SINGLE phase motor rating + the estimated converter losses.

This site suggests about 7A at 230V PER HP of single phase motors

https://www.engineeringtoolbox.com/elctrical-motor-full-load-current-d_1499.html