S'too early to be answering a technical question...
We are talking about the Research Skill right, the one where you go to City Hall...
So ... if you have two Research points allocated simultaneously - lets say A & B, ie B can be unlocked by visiting a townie, after you unlock A but before you go and look at A, I'm pretty sure, you wont be able to go back and look at A once you have unlocked B. B will supersede A at City Hall. There isn't a queue.
This can be good and bad.
If A is integral to your storyline and is a cause to open other effects, then that's not good.
If you like the idea of people having a choice eg go do Research A or continue on and look at B, and maybe failing a case based on that choice then it's not so bad and can be a good plot device.
Doomsayers 1? does this in some fashion.