I was able to ignore most of the references to options where you potentially share her in certain scenes but with the 4th rank permissivity training requiring semen from donors I won't progress further. Is there a more "exclusive" option I missed or is that the sole path forward?

You should be able to pick "I think you've successfully completed your training in permissivity; there's no more teaching you need for now" as long as you have completed at least one other Permissivity 4 training. Let me know if you don't see that or it doesn't seem to work.

When I reinstalled the last saves available were back on day 13 but I'll work back to that point and check.