Not sure if it works or not, haven't tested it yet, but if you go to your Strive settings.ini in your appdata/roaming/strive4power2 area you can change no_breed_incompatibility= to true instead of false and try that.
Edit: So yeah, this doesn't seem to work. Still get the same message about no pregnancy and such. Not sure why the option is there if it can't be used. xD