Congrats on the new offspring! It isn’t operating as intended with the immediate immobilization, for sure. In v.07 I’ve heavily reworked the Swollen system as part of implementing the “hidden pregnancies” feature. That is still in testing but should ideally fix the quick immobilization issues.
Regarding that, however, what is the Endurance of the immobilized Slaves? The new system calculates endurance and Strength, but the old one heavily relied on their endurance to “support” their increased weight.
Regarding the males, the old system calculated anal capacity as double that of vaginal, which is likely a large component of why they were less effected. Did the system feel more natural for them?