I've been testing out the <a href="http://fossil.include-once.org/streamtuner2/artifact/d33de0988618a4a68b00a7e2ab3f92c87cc4e0a6">history plugin</a>. It doesn't work
very reliable, but can keep the last couple played
stations under →favourites→history. So jumping back
to the previous one is definitely implementable.
<p>
Channel/genre importing as .m3u seems entirely feasible.
The UI doesn't yet support that, but I actually planned
on adding selections; which could then be exported with
the existing →station→save feature.
<p>
In the meantime a simple cache-to-m3u command line tool
might help. All station listings are saved as JSON after
all..