Basic concept is a Research Facility with an increasing time/cost per building researched but in turn your next Blueprint option is guaranteed to have that option.
-The general idea with this balance is that each time you research you would have to select the Blueprint before being able to perform the next research.
-A Reroll would push that researched Blueprint into the next set of 3(4)
Time wise, let's say, first Research takes half a year, then 1 year, then 2 years. So at most you would be able to manipulate 3 options but potentially with 2 other research options you would be able to cut down that time.
Say there is a Basic Research, Intermediate Research and Advanced Research. At the cost of resources you would be able to reduce the time.
Say at first research it took ,5 resources for 5 mins, or 15 resource for 3 min or 30 resource for 1 min.
Then the next tier would be 10/30/60 at 10/6/2 mins.
So basically you would have the option to balance between your stored resource or time, if you need X blueprint but can't spare Y resources, then you do the longer option knowing that when it comes you will be able to push through a strategy.
I guess from a visual standpoint, the way it could work is that on the Blueprint Screen, what you researched would show as a "Wild Card", upon selecting you would be able to pick any building from what you unlocked.
I feel this slight level of control would help with the overall balance of the game, there does just seem to be a problem with later game being "more difficult" because your rotation of building options is ever increasing.