Works just the same as normal apex, but its goods from a station, it takes time, and they charge a serious fee. You can only have one Apex hauler active at a time.
The size of the fee would be the problem, I think. Credit-earning rates vary so much between activities that it can't be sensibly balanced.
If you go all out for credit earning, you can probably get 200M/hour (there are certainly a bunch of stations with lots of missions that pay 50M each and don't take 15 minutes each to complete). So if you can normally make five round trips an hour, with a T-9 carrying 750t, that means to make it a reasonable choice Apex need to be charging something like 50000 credits per tonne hauled (or about a billion credits to complete a basic outpost for you)
Of course, the vast majority of in-game activities don't earn anywhere near 200M/hour. So that just makes it ridiculously expensive and means that you can't usefully do "other stuff" in general and have it be at all a useful substitute for hauling the cargo yourself. You're still either hauling or doing this extremely specific gold-rush activity.
But if Apex charge a smaller fee - say 5000 credits per tonne - that makes the fastest way to build a station (by a factor of ten) to use one of the outlier earning methods and then pay them.
Non-credit alternatives could work, though, because it's a lot easier to balance those to trade time-for-time. e.g.
- trade in a Building Schematic for 100t of requirements. Maybe could even be more than that, but there are a lot of spare Schematics about right now.
- increase the quantities given as commodity rewards for missions by about 10x, give the option for them to be delivered to one of your construction sites instead
- reduce the targets (slightly!) if building on/around a planet you've mapped
- have specific "construction convoy" signal sources with a pirate attack scenario. The more freighters which survive the attack, the more you get to your construction.
But the credit earning rates for activities are so incredibly unbalanced that it can't then be used to provide alternatives.