I have an ideal to add more flavor to your mod. My English isn't good so I will try to make it simple, I hope you understand

My ideal is to add a special resource that produce by the Academy. The engineer. The Academy now will demand domestic goods and a little supplies to function, demand isn't meet it will produce less engineer and officer training will slower.
The engineer will be demanded by military/insterstellar relay ,supercomputer, restoration dock,....to function at 100% and will less effective if the demand wasn't meet
And if it possible...the engineer could also count as a crew but with much higher payroll and cost to hire. They will give us some effect if we have enought of them in our fleet.
Let say your fleet need 100 crew minium for all ship to function at 100%
-> 10% of them is engineer : -5% supplies cost to maintain fleet
-> 20% : -7% supplies cost in maintain, -5% fuel used per light year
-> 30% : -10% supplies cost, -10% fuel used, +15% more resourse gain from scavenging ,40% faster and 20% cheaper ship repair after/out battle
-> 40% : -10% supplies cost, -10% fuel used, +20% more resourse gain from scavenging, fast and cheap like the 30%, +15% faster fighter replacement, 20% faster weapon repair in battle and 20% reduce overload duration.
Any more than 40% will not have any more effect .Let pay them 3 or 4 time more than normal crew to make it balance XD
Thanks for your awesome mod !
Edit : I think restoration dock should demand some heavy machiney, metal and engineer (if you decide to add this in your mod, of couse) to function and It give you +10% ship quality and some credit every month depend on colony size + fleet size of that planet because the dock not only fix your ship but anyone's ship. This version of restoration dock can only build on planet have heavy industry/ Orbital work.