Once the research tree is done there's no more use for science stations. our nicely built laboratories become moot. the perpetual science initiative would allow researching to continue (perhaps via a set of dummy research nodes at the end of the tree that themselves can't actually be completed). there would be 4 things to "research", each relating to the tier of research station involved. they would give consumables for use at a slow pace but very cheep resource wise. an example of possible research products is below.

Novice perpetual science gives one "micronutrient fertirlizer". (reasoning: study of dirt yields small amount of usable fertiliser)

Advanced perpetual science gives "tuneup chips" (reasoning: computer simulation optimising power system)

Applied perpetual science gives trace amounts of lead (reasoning: nuclear decay products and no vanilla way to get more lead)

Data perpetual science would discount a few seconds off the printing pod (reasoning: idk. couldn't think of a better one for this)