9soon-
Between your surgical healing, your short duration/high weight hanging, and some PE injury downtime over the months; you may have created some unusually strong and resistant ligs. While not definitive, there is a consortium of concern through various threads that short duration/high intensity hanging with too long of breaks in between could cause lig growth/strength without additional length—kind of a rebound effect.
If this were the case, it makes suggestions you are getting about reduced weight, longer duration, different angles, and injury avoidance all the more valid. As well, you might consider an ADS device, fowflers or repetitive hand-stretching spaced through the day to try to stay as ahead as you may of any rebound effect.
You once posted that the sensation of stretching you felt in straight hanging was bilaterally to the sides as opposed to centered. For you, that may be an indication that your specific present limiting factor is in the lateral aspects of your ligs. Again, if true, this would merely reinforce present suggestions regarding OTS hanging. I do note that you may use a scale-type apparatus as opposed to gravity hanging. This could give you an even better way to explore various side/up/down angles to identify focus on these stretching sensations. It would also give you the ability to use the fulcrum principals related above to the sides as opposed to top or bottom. (Again with reduced weight, longer duration, and plenty of respect for the safety issues of going off-axis).
—Good Luck