For me, exploration is getting anywhere without a having a specific destination to end with. Because traveling from A to B is exactly that, traveling. The adventure is the experience of the journey, not the destination. If that makes any sense.
It absolutely does, which is why it may have made more sense to make it not a specific location, but simply, a type of thing - that allows exploration, but with some kind of goal.
I mean, I was massively suprised when I recently had a codex entry pop up just from scanning a star, I was pretty sure I'd seen every type (and honestly it looked exactly the same as all the other orangish stars to me) but considering I've been playing since launch of the game, this kinda proves that there are star types and other things out there that are fairly "rare" which would be legit targets for this kind of thing.
Then you have exploration which is about just searching, no specific end point, but you don't just have "Go a certain distance - don't care if you find anything"
Also I hugely agree that the types of modification the engineers do are fairly dumb. Why does palin grant thrusters.... it makes no sense whatsoever, he should be giving grade 5 FSDs and heat sink capacity and scanner ranges. Explory/Xeno type things.
Scan a water world beyond 500 light years from Sol (or perform a frame shift drive super charge using a nuetron star) - unlock felicty who gives G3 FSD. (and scanner upgrade etc)
Scan an ammonia world at least 1000 light years from Sol - unlock Palin who gives G5 FSD (and special xeno cargo racks - scanner upgrades)
Just seems more logical to me.