I would suggest to load an autosave and set research to 0 empire-wide. Also scrap research buildings etc.
In one game I was also nearing the end and only needed a couple of useless techs. I therefore decided to halt research e.g. setting research to 0, scrapping/destroying buildings etc.
I do not know what to do about the benevolent skill, which gives research bonus to star bases except scraping them, but I guess you do not want to do that. 