Ability to remember your custom element instance

You can specify a default custom web instance via https://matrix.to/#/#misc:fosdem.org?web-instance[element.io]=chat.fosdem.org - but there's no way to tell matrix.to to override and use a specific preferred web instance if you've have one.

Start by tracing how matrix.to parses the existing web-instance[element.io] parameter and review the current custom-instance redirect behavior. Clarify how a preferred instance should be remembered, then verify that it overrides the default while unrelated redirects remain unchanged.

Written by the indexing model from the issue text.