TTL to differential converter (STEP / DIR / ENABLE)

Yes. that's correct but looking at the parport driver,
you may be able to do this by inverting the desired
output pin by using the out-invert parameter.

linuxcnc.org/docs/html/hal/parallel-port.html

[This would have the advantage that it would likely  work in reset mode
(which doubles the possible step rate at a given base thread rate)

Basically, the control works with the software-inverted signal, but this sometimes results in more or less lost steps.
Since it works perfectly with the Mesa card, the solution using RS422 or the ACT drivers would probably be more reliable.
What components would I need for a reliable solution, ideally with multiple channels per axis?