Is it possible to export your own posts to json or anything currently? I like messing with data for archival. If not is it a planned feature? Could I perhaps host an instance just for archival purposes? If so how could I use instance hosting to best export and save data in a machine-processable format.
I don’t think it’s possible yet, still an issue on github https://github.com/LemmyNet/lemmy/issues/506. However, there are 2 python projects that interact with Lemmy API that I see recommended, (a) https://github.com/tjkessler/plemmy and (b) https://github.com/retiolus/Lemmy.py. I have not used either but it might be doable to use those to get your data, or a good subset of it.
No it’s not possible with the current tools on Lemmy. You’re indeed better off askin the Lemmy devs on Github if you want a reply to that.