Only if they have a plugin that describes how to install them. Many popular tools are much more complex to install and set up than just downloading a binary and making it executable. For those you need to create a plugin for mise to be able to install them. Luckily, very often some other generous person has gone through all the trouble of learning how to make the plugin, going to the official repos, making a PR, and finally getting it merged. But if somebody hasn't done that already, it's painful (more painful than, say, an asdf plugin). It depends on the language, on the tool and system requirements, etc. Overall it's kind of a mess. Mise leaves you with the trouble of figuring all that out, rather than making some kind of convenience function to get the process started easily.
> Many popular tools are much more complex to install
I'm curious which dev tools you're using aren't installable with standard mise backends. 99% of dev tools I use don't require a plugin.
> (more painful than, say, an asdf plugin)
You can still use asdf plugins, I could use mise to install an asdf plugin right now with one line `mise use asdf:raimon49/asdf-hurl`. The mise registry is just a convenient list of aliases, even if it doesn't accept new asdf plugins, you don't need it to.
As Larry Wall said "make easy things easy and hard things possible"
For most of them there's nothing to add though, you simply publish tools on GitHub/Cargo/etc. and mise will know how to install them.
https://mise.jdx.dev/registry.html#backends has a bit more current info.