A lot of issues would be solved by making the Men's category into an "open" category, and the women's category a birth women's, androgen restricted category.
So, all transgender athletes, whether M-->F or F-->M would simply compete in the "open" category.
Set basic guidelines for androgen use for the F-->M athletes. Then just watch it to see if it becomes an issue.
This would also allow any super competitive women who wished to race against the men (and could keep up) to do so.