I think 'sex positive' is a wishy-washy term and ignores the people can and do feel many emotions - including sad and guilt and disinterest and other not really open positive emotions - about sex and sexual acts and that's entirely normal. Sex is complicated and has consequences, positive and negative. Just being positive or nonjudgemental about it isn't going to automatically lead to healthy conversation or ideas - the language of sex positivity is easily used to pressure people into being more 'open' to sex they're not interested in.
There was an article a few years ago on how teaching refusal - giving and accepting - is a vital part of consent education and the issues with ignoring that as it is so often overlooked. With what is going on in schools with child-on-child abuse on the rise and wide reporting of girls feeling coerced into these things, we need better than the low bar of consent. We need to discuss sex as something we do WITH someone, not to or for them, and a lot more.
I've had discussions about porn with my 12 and 14-year-old. I read some time ago that the average age of first exposure to porn is around 11 and declining and we've already had issues with local boys using porn phrases and ideas as threats towards girls at the park. They weren't particularly comfortable conversations for anyone, but I think they were needed. It was at the tail-end of our sex-ed lessons (until this year all my kids were home educated so it was all on their father and me and I'll likely do it with my younger two whether or not they go to school later as I think this is very important), and yeah, we covered sexual pleasure and masturbation (including the history of and myths around vibrators), along with many other things like dealing with crushes and signs of abuse in relationships, issues like yeast infections, vaginismus, tight foreskins, we discussed arousal incongruence and myths around hymens, vaginal tightness and 'blue balls' and the science around all of them. We discussed different kinds of sex and the benefits and risks of each, different stis and types of protection including gloves which get left out a lot, we discussed the laws around sex and images. We also watched videos of women discussing their experiences of difficult pregnancies and experiences of the postnatal period. We discussed and read about experiences of abortions, miscarriages, and stillbirths. They along with my 9 year old have discussed anatomy up to including the parts of the clitoris and testes and breasts. They've also done the menstrual cycle including the different phases and how it's likely to affect them, myths and stigma about it from around the world, and signs to watch out for conditions and common medications for those issues. We also have a book that has many stories of women's first periods. I could go on, I had several pages of links and resources when we did this, it took several uncomfortable weeks, but it gave both my child who never asks any questions and the one who asks all of them the information and language they didn't have before to discuss things they hadn't before. We had so many very awkward but amazing discussions while doing this and since then around these topics, it was so worthwhile even if didn't always feel like it at the time.
Personally, I think body and social education should be a priority and education around sex has both. For me, what to cover is all of it and teacher's should be well supported in doing so. By all of it, I'm including things like the issues with coersion in acts like anal sex, how very few women statistically enjoy being on the receiving end of that, even fewer mixed sex couples do it regularly, and the greater risks of bleeding, infection, and STIs. Some of that may appear judgemental, I've certainly heard discussions on how people who talk about disliking anal sex or even things like not wanting long nails on a sexual partner is judgemental, but I think kids deserve to know their bodies and what to expect and part of that is knowing the risks and knowing the emotions they have around it are probably shared with more people than they think. To me, that's far more good and leads to more healthy awkward discussions than any amount of trying to be just positive and nonjudgemental about the topic is going to be. I honestly don't think you can or should, boundaries and honesty are important and a vital part of this.