Simple solution-get a full size vintage machine to fit it instead.
A Singer model 15 or one of it's clones would be a good choice.
Going the other direction, I've wondered why people don't buy old cheap commercial machines to fit to frames as sort of a poor man's longarm.
Maybe it's too much work to adapt the mount to the machine and fit the motor to the back of the machine instead of having it hang below like they do normally.
Unless I was doing it for a living I couldn't justify (even if the money was available) thousands of dollars for a new longarm machine.
Rodney