the OP’s idea is something i was considering when the discussion started yesterday, but i had similar reservations as yours
it would be cool but not practical
but there’s another huge practicality issue, which is when are you doing the swapping and how are you determining it? also, why?
if you’re swapping cards, do you have to play a round then another with the option to swap? do you get to swap as soon as you see your opponent’s IDs?
if you swap decks, who gets to swap? what if my Runner A is good against your Corp A but weak against Corp B and Runner B is weak against Corp A and strong against Corp B? who gets to ‘win’ in this scenario by being able to choose? a blind choice before starting? how could we ensure that it’s a blind choice?
another potential option would be ID swapping, but many IDs (Geist, upcoming Freedom, etc.) aren’t really swappable, and often swapping an ID doesn’t really do anything in terms of helping a matchup
plus the variances in influence and deck size, and the above issue.
one option i could potentially see would be adding restrictions to your sideboard, so things like:
one copy per item in sideboard
cards in sideboard can’t be in deck
in-faction only and can only be swapped with in-faction/neutral cards in your deck
influence spent from sideboard and your main deck cannot exceed your ID’s influence cost
obviously not all of these would work together and some would work better if others were also added, but
i think since the game has not been designed with a sideboard in mind, it’d be really hard to add one in now. so many silver bullets are so strong because they have to take up deck slots and potentially do nothing. if you get the option to swap them in/out, that increases the value of them exponentially and removes the only real downside to playing them