With the exception of the items contained in "Hulls" tab each research item typically has 15 levels of research that take 1 day each to complete.
For older tech like shown in the attached pic this seems a bit ridiculous. New players to the game are faced with years or research that many have no clue what the value of research it is.
If you could reduce the time to research each level of old tech to say 5min - 1hr, this would add a 'sense of accomplishment' to new players that they are getting ahead and also quickly clear up the clutter in each tab as old items get completed. At the same time revisit the 'cost' of each items research. Some are way out of wack to the value they provide.