It's occurred to me.
When people make these lists of why someone might oppose gender ideology, say 1) medical issues for kids, 2) homophobia, etc,
and is saying some of these are ok, and some aren't, I think maybe they are seeing all of these as totally discrete and exclusive. Which isn't really the case.
I don't think there is anyone opposed to it, including the far right and fascists, who are not concerned about the medical effects on kids, or the safety of women and girls. I know it might be shocking to some but even fascists have normal feelings for their kids, wives, mums, and so on. So really, if people are working towards that with a far right person they are likely all on the same page there.
But I think the Real Feminists have realized that gender ideology has revealed that some of the elements in movements around women's rights or gay rights may have been on weaker ground than others, and that scares them. Some of the stuff around the idea that differences in male and female behaviour, on a group level, being wholly socialized, for example. Or some of the "love is love" sloganing, or the assumption that by some that the law must always be sex blind.
These ideas have been questioned more by some people who didn't before. Personally, I think that is a good thing, movements always have some elements that are stronger than others and it's normal and healthy to shed the less robust stuff. You get a stronger set of ideas, more in touch with reality, at the end.
But I suspect this is what some of the Real Feminists may mean when they say that the Far Right will be spreading their ideas. They mean, they may point out some weaknesses in the Real Feminist, or actually in the left wing position. And people might listen. They might listen to a Jordan Peterson lecture and decide he isn't actually completely out to lunch.
As far as they are concerned that is being infiltrated by the far right.