Soft starter question

I just purchased an American Rotary ADX 25hp phase converter for my shop.

Right now the largest motor in the shop is a 10hp motor on a planer, followed by 7.5hp motors on a dust collector and lathe, a 5 hp saw and a variety of .5 - 2 hp machines.

I’m now looking at a 15hp lathe. I like the lathe for its swing and distance between centers, but will never take a cut with it that requires 15hp. I would prefer not to go phase converter shopping again, so am wondering if it would work to put a soft starter on the lathe’s motor, or if there is another solution that would make sense.

There will never be a time when I have 25hp worth of motors running at the same time. My concern is really on start up and making sure my phase converter will be able to start the 15hp motor.

What is a smart way to move forward?

American would be the definitive source, but if it's a 25hp RPC, I'd bet that it's start a 15 hp motor. If not, adding the 10 hp motor should do it, if not, adding the 7-1/2 motor ...., you get the idea.

It's doable with what you have.