Note that once you have built the exocraft and an Orbital Exocraft Materialiser room on your freighter, you can just summon the exocraft whenver you want as long as the freighter is in the same system as you.
To get all the new freighter rooms researched, I had to farm 15 or so Salvaged Fleet Units. I decided to this by trying out piracy, which ended up working so well I almost feel a bit bad about it…
I put my freighter in a pirate controlled system to avoid sentinel involvement. Then I blasted freighter storage pods as soon as freighters warped in. Salvaged Fleet Units are pretty rare, but the freighters are plenty so it didn’t take that long.
Once I was done, I landed on my freighter and teleported to a non-pirate space station to sell all the illegal goods I had gotten at from pods not containing fleet units. That gave me more than 200 million credits. And that’s in addition to all the materials, frigate fuel etc I also had gotten.
I even managed to get quite a lot of faction rep by killing the bounty ships that spawn quite frequently in pirate systems.
Man… farming is sooo easy in NMS compared to most other games.
In fact, you kinda have to farm Salvaged Frigate Modules via piracy, which imo is unfortunate. You can try to limit yourself to the alternative sources to avoid piracy for roleplay purposes or whatever, but getting the modules via non-piracy sources can be extremely slow due to unbalanced drop tables.
If I’m understanding you correctly and one of the (cosmetically) big freighters is what you’re after, then just avoid accepting the very first freighter offered via distress call/battle, and the next warp-in scripted rescue will involve either a Venator or a Dreadnought (those are the two large models that everyone seems to want).
A couple updates back (the Sentinel update, I think?). Since then there’s a “quest line” that unlocks modules for the mech that allow for it to work autonomously and aid you in combat.
Just 6 days left of expedition 8 “polestar” (the freighter expedition).
Heads-up in case more people than me postponed starting it since it had so much longer deadline than the earlier expeditions.