I'm not saying that allowances are made for women. I'm saying that in marking, allowances are made for smaller people at all levels. Over and above this, skill and experience is taken into account at kyu grade level.
I see no reason to make allowances specifically for women - except perhaps at kyu grade level as women and older people are often starting from a disadvantage.
It's use of body dynamics that counts - not how much power you produce. Someone big and strong with no training at all could produce a considerable amount of power. That's not karate - it's just throwing your weight about. As I say, if it just came down to brute force then big guys would win every time, but in kata it's frequently below average sized people like wee Garry and Graeme that do best. (Hey, I guess i'm saying it pays to be biologically inferior for kata

)
The same thing happens in kumite. A small guy would never do much damage with a chudan punch against a big bruiser. So strictly speaking, chudan punches should never score against a considerably bigger opponent. But they do if they're technically correct - ie if the small guy has produced enough power relative to his strength/size. Conversely, a big guy could quite eaily deck a smaller person without any technique at all. But it wouldn't (or shouldn't) score in competition.
Do you even know what power looks like? What looks strongest is often very weak in reality. Typical 'Kyu grade kime' looks impressive, but it's actually counter productive.
I can't comment on the peformance of the UKTKF kata champion. I didn't see it. You saw how upset wee Graeme got at the merest suggestion that someone might have preferred her performance to his - you certainly back peddled fast enough when he challenged you (top marks for agility by the way). I think it's reasonable to assume that she might be a little hurt at having her performance ripped to shreds and the validity of her title questioned. Why not just congratulate her?
I think you're starting to see now why direct competition is so important. Without it there will always be these doubts raised over womens' abilities in karate.