There's a lot more to being in a special forces unit than just the physical. There's the mental, the team trust among other things that's needed for them to function like fingers in a fist.
I'd be very open with this, I don't think the standards should be lowered at all. Maybe adapted for a female special forces unit but the male unit should remain with their own threshold. If you watch a lot of documentary about the special forces community, they function like jocks in sports team and they have complete trust that their buddy can move, communicate and shoot as good as they can so no one is watching their back twice because they know the next guy is just as good. Lowering standards of any sort jeopardises this set up in my view and that brings its own can of issues.
Of course, there exist things that women will be great at if not better than but that should not come at the cost of the physical rigour that's required.
Also another thing to consider is that fights that special forces are involved in are never fair fights. This isn't sports where people look for fairness, it's best to assume the enemy is going to hit you with the worse of what he has. You being able to move quick with all your gear, communicate and shoot like a special operator requires the best of the best. In fact, why is this even a thing.
There exist plenty of specialist work such as MI6 where the ladies may work closely with special forces unit to find baddies or whatever.
If you're doing it on the basis that they're "not as strong but they're probably as good or better in every other category", then you should lower the requirements across the board because that statement would apply to the male candidates who couldn't pass the endurance test as well. If they're not willing to do that for the men then they shouldn't do it for the women either.
This is dumb, the standards are what they are for a reason, to lower them to let more women in is an insult to the current SAS and the women trying out and also potentially dangerous for the squads sent out.
The requirements should be daunting too, the job these people are expected to to is extremely demanding both mentally and physically, usually both at the same time. Just look at the Navy SEAL program, combat roles were opened up to women in January of 2016, and exactly 1 female has applied and she dropped out in August.
I would be shocked if there weren't any women who could make the cut with the standards as they are now.