I had this kind of thought for a while but with mechanics coming out such as Alliance type in Mumbad cycle and the mini-faction runners, I wonder what it would be like to have runners that are a ‘Dual-Faction Runner’ (i.e someone that can be from two of the three main factions via having two sides of the same ID like flip IDs but only goes towards Deckbuilding purposes and cannot be flipped due to then sticking with that one faction for the game but has the same ability for both factions he or she chooses)?
An example to explain it better is John/Jane Doe runner is both from Criminal and Shaper. Both have the same ability (gain one credit when the Corp draws a card not through a card ability). When creating a deck for that ID, he or she either choose either Criminal or Shaper as their faction in terms of deckbuilding and play. So either the deck would consist of a majority of Criminal faction cards or Shaper faction cards, having to spend influence on cards on are on their other side if they did not choose that Faction during deckbuilding.
There are some restrictions and downsides that might be added: The runner might have more influence but cannot include cards out of faction from the other major Runner faction (So John/Jane Doe of both Criminal and Shaper cannot spend influence on cards from Anarch).
Tell me what you think. And hopefully I explained the idea well for you.