I don't think the Kama Sutra can said to be literally indicative of sex and sexual positions on the middle ages, for the basic reason that it's largely anatomically impossible. Firstly in terms of leg flexibility, backbends and so on, and secondly the fact that in a lot of images, the woman's vagina is on the front of her, facing forward. e.g. https://www.alamy.com/kama-sutra-illustration-19th-century-unknown-290-kamasutra42-image188817253.html [NSFW] . In the Kama Sutra, there are images of people having sex standing face to face, flat-footed, legs together, 20cm away from each other (their genitals are the exact same height). This isn't possible, so I would be careful about how much you draw about the reality of sex in this time from depictions in the Kama Sutra and similar. (Another version is a position that people can get into, but from which neither partner would have any leverage to move).

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Presumably married people at least knew these images weren't realistic. Whether that means it was intended to be symbolic of feminine and masculine properties of the universe, or whether it was just meant to be symbolic of, well, sex. (Compare an cartoon now of a woman with physically impossibly large breasts. It's not an indicator of women's real breast size, but it does indicate something about our ideas about sex. But in another time or place, and found in a temple, it might represent fertility, and that might have more to do with a good harvest / animal husbandry as much as human fertility).

Then we have the sex tips in Cosmo (women's magazine), which sounded plausible and exciting to teenagers who read them, but as an adult you immediately understand no one is doing these. (Some of them are perfectly possible, obviously). Again, an anthropologist would learn something about Western 20/21st century sexuality from them, but not if they took them seriously and literally.

And there is also the example of porn - especially written/drawn porn - by someone who is inexperienced in sex. (For some reason, people post these on Quora a lot as responses to questions, so I've read a few.) It's claiming to be a factual anecdote about a real event that happened to them, but anyone with any sexual experience will recognise it as fake. An anthropologist should be careful in what lessons they draw from such depictions of sex.

Hopefully an expert will answer your actual question, I just wanted to challenge the assumption that we know what people's actual sex lives look like from the Kama Sutra.