shouldnt affect the others at all... at the default 25khz kernal speed the nomiinal cycle time is 40uS so a pulse width of 10uS isnt going to be an issue. Most stepper drivers need a pulse width of not less than 1 or 2uS but as they are edge triggered the larger width isn't an issue.

I thought that the pulse width might be the issue at that lower frequency. I am surprised though, I would have thought Roy would have put pulse-width conditioning if he was doing frequency to voltage rather then pulse-width to voltage conversion, I would have, but then I'm not designing for commercial supply (since he knew that pulse width can be adjusted in MACH3 maybe thats a cost he didnt need to bear).