What a great presentation.

Thank you! It was fun putting it all together.

Let me answer your question in two parts:

worthwhile to a lower BR player?

Had Icarus been available two years back when I started, I'd have gone straight for it, totally skipping the other two jets.

Icarus has a great cost-benefit ratio, you're fully operational (full boost height) from the start with only 50 certs invested (higher levels speed up recharge time, so you can faster chain jumps together), unlike the others where you only unlock full air time (drifter) or fuel capacity (jump) with the last level, each level giving you only a piece of the pie.

That makes Icarus a great jump jet imho for low level players who don't rake in certs like us experienced players. You don't have to go all the way at once, I myself have only certed it until level 3 (50 + 100 + 200 = 350 certs) so far and it's totally usable. The last two levels are nice to have, not a must have.

does it have any legitimate advantage over the other jets

Drifters are way more situational and niche than Icarus. There is always a roof or rock or other structure to jump upon, even indoors traversing staircases or tower levels can be sped up with Icarus. Drifting on the other hand, there are seldom any worthwhile targets to offset the risk of slowly floating through the air. I had the least airtime (and fun) with drifters so far. The movement isn't my thing and you're too easy to kill because driftes necessitate a very exposed playstyle which I'd recommend beginners to stay far, far away from. (Or maybe it's just me that sucks at drifters, not ruling that one out.)

Compared to jump jets, neither Icarus nor JJs are better than the other, it all depends. If you want to scale large and complicated structures where you can't reach your goal in a single jump, like the main building in tech plants or rocky cliffsides, or if you want to slowly creep up something, JJs are definitely the best tool for the job.

Icarus on the other hand is great for when you want to move in fast but short bursts. Quickly jumping on buildings, walls, balconies, switching levels in towers. Most bases are well suited for that playstyle, you can quickly take to the roofs to engage in top-down fights or use Icarus as an "ejection seat". Round a corner, full thottle, you're gone before the guy chasing you realizes what's up.

Putting aside the cost-benefit advantage Icarus has, the more important question is: Which jump jet fits my preferred playstyle?

Well that is something everybody has to decide for themselves.

To sum up my opinion, if I could do it all over again I'd get Icarus (short fast jumps) first, JJs (slow deliberate movement) second and drifters (look Ma, I'm a parade ballon) just as a novelty item.