Thanks for the reply. I just want them for general prusik backups on 8 and 9mm tethers, and also to do some experimenting with a 2TC setup. I prefer sewn as I do not like the bulk that a knot can add, and I also tend to trust the sewn loops more. Just personal preference. I want them in several different lengths to have options, but they are quite hard to find like this, at least in that diameter. I may end up just special-ordering a bunch from a third party splicing firm and selling the extra.
Your ascender knots are interesting, but likely a bit overkill for my needs.