I still need answer on one question, can research be used instead of a building to decide factions in this case?

About the three seconds to not delay time in game and give player an opportunity to cancel their Faction choose you suggested 3 secs and I suggested that 3 secs could be removed from the cybernetics core build time to remove the time consumption, maybe 4 secs removed to compensate for choosing faction.

An other question you didn't answer is about this choosing path A and B, choosing one of them you said that the button would be disabled.
How does it look when it's disabled?
is it Grey, or clickable without effect or gone?

I stated this before: yes, researches can be used instead.

The 3 sec suggestion is only a suggestion. Do whatever you want.

Before I proceed with addressing your third question, I would like to remind you that I have no obligation whatsoever to help you, so take care not to phrase your words to make it seem as though you think I do.

With that said: I don't know and I don't care to find out for you. If you want resources with which you may investigate the properties of buttons and their interactions with the states of research, I can provide them, provided I am in an amiable mood.

Guess you don't know how it will look like when a button is disabled by a plugin, that's all right, at least the button wont be possible to be used.
I'm well aware that you don't have an obligation and thank for your replies as they have been very useful for my knowledge and possibly others.
I think I got all the answers I need and some additional ones.