With the not-so-new-anymore changes to prep vendors, Squad Engineers can really tailor what they want to carry into the field. Gone are the days of a common pool of supplies that get monopolized by the first asshole to weld the door shut, leaving latecomers high and dry. While a lone squad engineer might feel a bit of a pinch compared to before, two or more engies can definitely bring more to the table together, and latejoining engies actually get to feel like equipped engineers rather than glorified PFCs.
Here's some examples of the sort of loadouts you can take. Feel free to share your own!
The all-rounder aka "I liked hogging all the stuff, damnit" loadout
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1 mine box (18)
2 C4s (10) + 1 C4 from essentials
10 plasteel (7) + 10 plasteel from shared prep
Rangefinder (10)
Supercapacity power cell (hack the vendor)
PCM (get from a generous MT or dismantle a maintenance closet APC)
50 metal (req)
1 incendiary grenade (req)
The Kesserline Seagull Special aka "MINE MINE MINE MINE MINE"
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2 mine boxes (36)
1 AP mag I guess lol (6)
2 more mine boxes (req)
Even more mine boxes (also req)
The Maximum Unga aka "Really a PFC in disguise" loadout
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5 AP mags (30)
2 more AP mags (12) or Rangefinder (10) if you like mortars and OBs I guess
Large mag pouch (ask your Specialist nicely)
Even more AP mags (req, don't tell them about the AP mags you already have)
The Autismfort aka "I actually enjoy FOB duty" loadout
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50 metal (25)
25 metal from shared prep
20 plasteel (14)
10 plasteel from shared prep
All the metal and plasteel and sandbags req is willing to give you