Two more options to throw out while I work on putting some real companions into Schattenlander...
One that I had been considering, and may still use for other stuff, was a Tracking-based spawn script on the map that would periodically spawn "possible campsite" pseudotowns within a short radius of your party, and then remove them once you were twice that radius away. And have those be your campsite. The higher your Tracking, the more often they come up and the shorter the radius to them when they spawn. The nice things about this one, IMO, are (a) you can't quite camp anywhere... with suitable modifications, for instance, you'd never see a possible campsite within a certain distance of a town, or (for non-schattenlander mods) an enemy party. But you can reliably find a campsite if you want one, it just may take walking and patience if your woodscraft is poor. The other advantage is that (b) you can actually have a campsite scene. Standard random scene plus some 'log' props and a modified hearthfire. And of course (c) it has no problem with solo play, although as Fisheye said we've got lots of other things in Schattenlander which assume you'll have at least one companion, generally more, so that's essentially a nonissue.
Does anybody have a "sit" (and stay sitting) animation coded in any of the mods around here, btw? A static pose would be OK.
I may still write this script for the various wilderness features like shrines and caves in Schattenlander, so if anyone's interested in using this mode of camping we should get together on it.
The other suggestion is that rather than have a "_" troop, label it: "Packhorse." Heck, make him an invisible companion troop mounted on a sumpter horse, with a script to repeatedly set his HP to 0% despite your best efforts (and some exceptions in the post-combat code so he never gets allocated XP), and of course lots of Inventory Management. And some amusing one-sided dialogue, no doubt. That would be pretty cool. Especially if we can come up with a workaround to do companion item exchanges without money changing hands.
(Hmm. "Exchange items" dialogue option spawns a fake party for a fake combat, (start_encounters) it with its dummy lootable troop, puts all your companion's items on it, loots it, puts everything back, goes back to dialogue/menu where you came from? Could work... anyone who can write a generic "trade without paying" script would be hailed as a saviour by any number of mods.)
The nice thing about the packmule being that he's optional. Set his Riding skill to be equal to the player's (he's your pack-horse), and he won't slow you down much. And if we can get the above exchange-items script working then we ought to be able to do "loot pool" code like Fisheye was working on, where you can dump stuff to the packhorse and then menu back to the looting screen for more. Which would make a ten-Inventory-Management mule honestly a pretty worthwhile companion a lot of the time...