Jez, I'd like to propose an alternate idea.  Bear with me because this might not be in the exact spirit of what you want to do, but humor me if you would.

A limited mobility container, perhaps one that can travel slowly (10-20 kph) if given a navigation order would be adequate.  Versus a static container, they should have some trade-offs for their mobility.  Perhaps limited range based on some idea of fuel or battery power.  Confine them to say, moving 500 to 1000 meters before they expend an onboard fuel cell and become stationary.  For the benefit, they might be more expensive to purchase.

That aside, the ability to just pick up or drag a container to place it elsewhere seems my preferred solution.  The needn't be done in some special way.  Just give us the ability to take current containers and put them elsewhere.  Though having a container on tracks with an adorable mini-Sequer head would be more graphically amusing.

Please keep in mind that in that "other" game the Orca required a pilot, so in comparison then, the group would need a specialized cargo mech that can allow for secure tabs and permissions form various ones in the group to view, add, take, or organize the individual tabs.

I think this mech will be necessary in the future growth of industry and mining but seems a bit premature.

I would suggest a can feature that allows you to stack like items in the can. (and I don't think the field can we have now should be able to hold more than the sequer)

I would also suggest a much more expensive can that lasts longer (hrs) and has 2 storage areas with separate tabs and security features for larger groups.

I would also suggest a module that allows you to "anchor to, and tow" the can to another destination should the need arise.  This module could be fitted to a hauler and when in tow mode, could limit the speed of the mech by 75% or so

I would also suggest a station can for a hauler toon to mark and separate goods he may be hauling for multiple pilots but has to stage the goods in his hanger until the op has ended.

+1 for Tow rope mod...

Indy slot looks like a wire rope.
T1-  -75% max speed
T4-  -25% max speed
Allows for field containers to be dragged to another location.

Or a Winch mod
Indy slot looks like a spool of wire rope with a hook
T1- able to pull 150M per cycle (pulling bot must stay on destination tile)
T4- able to pull 500M
Allows for field containers to be pulled to a new stationary location.

Sure I wouldn't mind an orca style mech, but it should have limited cargo capacity unless deployed, shouldn't be able to exchange gear while not deployed, should take a minute to deploy/undeploy, and can't undeploy if it has more cargo than it could ordinarily move.

That way you could use it as a mobile can but would still need haulers to empty it regularly and couldn't just keep it in motion all the time.

Yes, repack and redeploy would be teh hawtness!