And their takeaway was that there needs to be some advances to smooth out the annoyances, not that the idea itself was flawed.

Think of glasses. Glasses are used to increase people's ability to see up to the human norm, not beyond it, but besides that difference there's very little to distinguish eyeglasses from an embedded magnet on a fundamental level. Both are about increasing your capability, but nobody is attributing people getting tired of wearing glasses as a problem with technology itself and transhumanism as opposed to a limitation of that specific technology, and it's just treated as a downside you attempt to mitigate because the positives are to well understood and accepted.

The argument against transhumanism is that conventional 'external' technology is more flexible and convenient, and glasses are clearly in the latter category.

I'm not against transhumanism as such, to an extent it's inevitable for medical reasons. I expect we'll gradually build up experience from medical implants and a minority experimenting with body modification, and eventually a consensus on useful mods will emerge. I think it's going to be a very minority thing for a very, very long time though. All of my lifetime and probably those of my kids. Technology is advancing too fast for it to make a lot of sense to surgically commit to current generation tech right now, except on an experimental or critical medical basis.

To me, that's less an argument against transhumanism than it is people drawing an arbitrary line and deciding the things they don't like can get one label while the things they do don't, so they can easily point out problems even though the line is mostly arbitrary.

Whether I get some small extra perception because of a simple small magnet or because of a complex microchip is irrelevant to the point if they provide the same new abilities and have similar levels of risk and robustness.

Similarly, whether we think getting social media embedded in your consciousness or getting a gun embedded in your arm are good ideas has little to do with the prior examples, so to me they aren't examples of problems of transhumanism as much as examples of problems with humans.