would it be possible, if hot key swap through different variations when pressed multiple times of the same type once they have been researched? e.g.
6: bridge > lava bridge > ocean bridge >bridge ...
4: tunnel > water tunnel > tunnel
similar for splitters and manipulators - even though there are many variations - maybe limit it to the most relevant
2: splitter > corner splitter > tripple splitter > 3-way splitter
#hotkeys change through different variations
lime cipher
scenic bay