I don't know what the problem is. Haulage ships? I collected the mats I needed after gunning down WANTED haulage ships... which included Cobra Mk III and Asp, so don't think it's exclusively ZP Haulers.

Those NPCs done wrong, so no atrocities committed. All perfectly legal and above board.
The Problem is that People dont want to go around doing Different Jobs.
An Explorer does not want to Kill People.
But he wants an FSD Jump Range Upgrade.
An Upgrade which is gotten from Materials that Require you to go. Surface Mining, Kill Transport Ships and Scanning High Wakes.
3 Different Jobs. Now the Surface Mining falls somewhat into the Explorer thing.
But High Wake Scanning and Killing Transport Ships ?
Most of the Upgrade in this Game are only Available by doing 3-4 Different Jobs. Jobs which partially require Different Equipment and most of the Time are not even the Job which your later on Doing with that Upgrade lol.
Take the Laser Damage Upgrades for example. They all Require you to do Surface Missions and Attack Surface Bases to get the Firmware.
From a Game Designers Viewpoint. This Design Screams to me. "We want to Force the Player to Play all the Content and not only the Part that he wants to Play"
The only way around doing that. is to get the Materials from USS or Missions which Offer Random Materials dependent on a Systems State and thus usually take alot of Grind and alot of Repetition before you actually get the Stuff you want.
And sorry but this is Horrible.
I will likely never get an Engineer Upgrade. Simply because I am working and only have maybe 2 Hours per Day for Gaming.
2 Hours I sure as hell wont Spend every Day for WEEKS just to get Materials for one Upgrade.
The Current Engineer Mechanics are the Same as the Ship and Equipment Prices.
They are Illogical and cause an Insane Grind.
And sorry. But thats Rubbish.
Especially because all of these Materials are Apparently basic stuff and Ship Components. Why the cant we just Buy this Stuff ????
I mean 99% of this Stuff should be Available for Buying at Stations.
Scavenging for them should of course be Cheaper. But you should be able to just Buy them.
This whole thing Screams that the Devs somehow wanted to use this to Artifically hold Players inside the Game for an Extended Period by making an Unimaginable Grind out of it to get this Stuff.
And Sorry but thats not Fun or Entertaining. Its Boring like Hell and Frustrating.
The Engineers could be such an Great thing adding new Content to the Game and new Depth to Ship Customization. If you could just Buy those Materials which would Create an money Sink for Rich Players to Modify their Ship. And at the same Time make sure that those who Scavenge and Mine for the Stuff get it much much Cheaper or can Simply Sell it for Cash if they dont need it.
Instead they made it a Grindfest that many Player Outright Refuse to even bother with.
From the Introduction of Engineers to the Material Gathering. It makes no Sense and is Only Grind.
And Sorry but thats Rubbish.