Not possible I'm afraid.

Of course it is. There is only planet module roles for military and civic labs (or whatever you want to call them), and military and defense are hard coded to use one, Civic and Diplomacy the other, and fleet logistics can use both.

The key to modding Sins is learning to deal with these constraints in creative ways to get the effect you want. You will have to keep what you want to do flexible enough to go around these hard codes, if you're set on wanting something done a very specific way you'll become frustrated very quickly.

Many parts of the game are not very flexible. And research is perhaps a bit less flexible than average, but no where near the least flexible.

You can set which tier the particular tech is (and you can place it anywhere on the tech tree, a tier 8 tech can be in the first column for example), and you can globally set how many research labs are needed to be able to research a given tier. But that's it. If you wanted to have just one race have very good research but need twice as many labs, you'd have better luck editting that race's research lab so that is takes twice as many logistical slots and costs twice as much. That's the kind of approach you need to take to modding. Same net effect, just perhaps not your first choice in implementing it.

There are only so many slots available

Well...the idea was to make research a little more challenging so...