So I went to map and tried to map route to it from Luyten's Star.
Route failed!!!!
So I tried to find stars half way. I did this several times not realizing I was plotting stars not on the same plane. Finally when realised that I had actually gon eback closer to my starting point did I throw the towel in.
I've been playing this game on and off for YEARS!
2. How do you plot an un-route able route?
When I typically get a
"Plotting Route Failed", it's due to a locked region getting in the way. I went to visit Chloe while I was Crystal Shard Mat Farming out in HIP something-something, and couldn't plot a route due to the locked region of Col 70 Sector I think it was. The only way around it that I'm aware of, is to manually go under, over, or around the region, or use one of the 3rd party sites. If you get stuck into a situation like that.
Here's a link for the known
Permit Locked Regions.
At 17+Ly Jump Range, It does get harder to jump the further "up" or "down" the plane you go, but you should be able to jump in that region, although I personally wouldn't with anything less than around 30ly if possible. Unless absolutely necessary and/or can only be done on that ship, of course.
As others have also stated, you're better off with Felicity or Elvira, it's entirely possible you engineered your FSD under the older Engineers system, I'm still overhauling my fleet to be fully up-to-date (except the odd sweet roll here and there that matches the ships' new outfitting). If so, you'll have Mass Manager to add also.
I recommend checking out
Inara's Engineers Page and ensure you have the relevant Materials, assuming you've unlocked said Engineer, and it may be useful for you to install and link EDMarketConnector to your Inara Account and let it live update your game statistics. Especially helpful for finding stations/commodities etc near the system/station you're currently at, as well as showing you via the Engineers Blueprints, whether you have enough materials for said module.
The Guardian FSD Booster will open up
A Whole New World and make you sing that song, even if momentarily.