This is a very difficult topic. I think intention can be everything (cruel pisstake or genuinely affectionate portrayal), but either way, it's the resulting effect on the "community" being portrayed - whether that's people of colour, or women, that counts, not the intention of the person in drag/blackface. The problem is, there is no unified view on drag in the "community" of women, so for every woman who hates it, there is an equal number who don't see the problem.
There's a much more definitive view on blackface in the "community" of black people (that it's wrong, whatever the intention); however, in the wider community of human beings, many white people continue to not see a problem (e.g., Justin Trudeau, the wokest of woke political leaders, couldn't see the problem until it was spelled out to him).
I went to a party recently. There were 2 white women there portraying black women. One was there as Mel B (so called Scary Spice). She was dressed in a leopard skin outfit, the typical style of that singer. She did not wear black face, nor did she wear an afro. She didn't "act" in any way other than herself, apart from going into character for photos (typical Spice Girls type pose). So her portrayal was more or less just clothes. For the purposes of the event, however, she was saying: I am a black woman, Mel C.
The other was there as Sinitta. She wore jet black paint all over her body (nothing like Sinitta's skin colour) and an afro, as well as an 80s outfit, apparently relevant to that singer's style. She also seemed to be acting "in character" all evening, although that character didn't seem to be anything like the impression I have of Sinitta. Nevertheless, she was, for the night, saying, tonight, I am a black woman, Sinitta.
Both their intentions were good (so I understand). But were they both racist? In the Sinitta example, yes, undoubtedly, even if unintentionally. In the Mel B example, I am not so sure, to be honest.
So drawing an analogy with drag: In scenario 1, is donning particular clothes to be a particular black woman racist? Is a man donning particular clothes to be a particular woman misogyny? In the absence of any other cosmetic embellishments or character behaviour, just the clothes, is it wrong? Just to be clear, neither party is being themselves in this scenario (so not like Julian Clary, who is just being Julian Clary when he wears a skirt), they are being someone else. Or, is it the behaviour/character portrayal/physical embellishments that is the terrible part - the grotesque aspect (in the Sinitta example, the black make up and wig, in a drag scenario, the exaggerated "female" behaviour, e.g. Widow Twanky nagging/fainting/flirting)? If it's the grotesque aspects that are the problem, this seems to be a sliding scale|: at what point does someone tip the scales?
Here's another example of the sliding scale: Robert Webb doing the Flashdance skit for Comic Relief. He did the famous dance, but he also wore a leotard, which indicated female. Was he just being Robert Webb wearing a leotard, or was he saying, I am portraying a woman?. He wore a curly wig to have hair like Jennifer Beals, who is mixed race. So, was he not being Robert Webb? Was he saying, I am being the character from Flashdance, a mixed race woman? IIRC, nobody has condemned it as sexist or racist. Is it because the intention was kind (Comic Relief)? That the dance performance was unexpectedly good? That it's Robert Webb, whom everyone seems to like? It was a grotesque, talented dance aside, he was doing an exaggerated version of Jennifer Beals' acting/dancing performance. Is it that most people don't realise she is black? Is it that most people don't care about a woman, whatever the colour? Why didn't he tip the balance?
PP said History of drag in theatre goes back such a long way. Some are grotesques, yes, but they don’t say all women are like that, just the character they don with the dress and make up.
Does it matter whether it's a real life character that's being portrayed? If not, is that a free pass for blackface, as long as it's not a real person or "not all black people" ? There's a long history/tradition of black face too.