Why are you trying to maintain an instance list? Just ask the user to input their instance URL. It will simplify the code and make it extensible to self-hosted instances and you don’t have to try to list every lemmy instance in existance.
It’s a script that you put in place of the raw url of a bookmark in your browser. For these ones here you’d make a new bookmark and past in the script there (adjusting the fediverse url for your home community so it can correctly redirect you) and it runs some (usually) javascript that manipulates the page your on in a way to direct you to the asked for location.
Its a much more lightweight way to do a single thing if that’s all you’re needing and since you can see the code you can also be sure, unlike a chrome plugin, that it’s not doing other weird stuff.
I find Nix to be a really esoteric platform that completely inscrutable to a regular user. The people who do use it are extremely hostile to any tools that simplify the experience for the end user like Fleek. I would not recommend it for ANY regular user in any way, shape, or form.
The requirement of managing an LDAP or AD directory service just to get some auth for NFS is a dealbreaker for like 99% of people. It’s such a dumb protocol for the average user and was designed with only huge corporate clients in mind.
Just give people a simple password auth or let them exchange private/public keys between the devices that need to connect!