Sometimes a quest or event or some such will give you a free tech, but the game doesn't tell you which one. It'd be nice to know what tech we got for free!

I always wanted an option to abandon those quests. Don't like my game plan being slightly ruined by unpredictable filler techs.

The filler techs apply the normal increase to future tech costs right?  Could be why they don't seem as much a benefit as they're perhaps meant to be...maybe it would be a better reward if those quests just gave a huge chunk of science points instead?  Or maybe a minor cost reduction for one research quadrant for so many turns or something?

But don't all of these quests offer an alternative way to tackle them? A choice that does not grant a random tech as reward?

I agree, I would quite like to know what tech I've received when I receive a tech!