For a more exclusive and larger overview of all options, including a preview of the improvement's actual effects on current system & how many applicable planets would gain a benefit from any possible improvement, I would suggest to think about a "Detailed System-Improvements Construction Menu".


It would be accessed by clicking a button alongside the top bar of the current improvement-options box in the system view. The GUI would expand to half the screen size, overlapping the lower half of the planets, while not overlapping the left system info box.


As stated, the main purpose would be to see all the applicable benefits and outcomes on one screen without having to manually hover over each entry and manually calculating the effects. 


E.g. an improvement that gives +2 per sterile planet would show +4 in a table column for a system that has 2 sterile planets colonized.

An improvement that gives +1 science per anomaly would show +3 if there are 3 anomalies in the system.


Since it only covers half the screen, the planets in the background could be highlighted when moving over a specific entry, when they benefit from it, and even how much they benefit.


In terms of formatting, a table could be used, that just lists all improvement options, with tabs that act as categories, and with filter checkboxes at the bottom.


The table could be filled like this: 

A picture in the first column, followed by the name of the improvement in the next column, followed by standard effect, followed by the specific preview info tailored to the applicable effects in the current system (as described above).


Clicking an entry would add it to the construction queue.


Right clicking would shrink the box back to the current known size and functionality.



As to tabs and filters, the tabs would be categories like FIDS, happyness, military, while the filters would be options like "Anomaly related", "Moon related", "Fertility related", etc." and those filters would be used via a checkbox that is ticked on and off.