There’s also c) have people start using tags like #technology more frequently in their technology related posts, and implement support for subscribing to a tag (that’s something Mastodon already has, so it should be possible).
Tag thread feeds (like https://kbin.social/tag/technology/threads ) show content cross-instance and cross-magazine, and they also have the advantage that you can add multiple tags to the same post, no need to repeat the post to have it appear in multiple tag feeds.
Another tip: you can subscribe (or block) based on the domain of the link posted by using /d/<DOMAIN>
This also works using a lemmy/kbin instance as domain like https://kbin.social/d/startrek.website or https://kbin.social/d/ttrpg.network …although it doesn’t really refer to all communications with that instance