Basically when you do /waste , it could send you to the least visited outpost, so new players can get the most out of the waste, and mining. Unless you type a specific outpost of course
The servers with the most availability can be easily measured with how many residences are available in that server. How could it do the same with the wastelands? There isn't really an easy measurement to use there.
Perhaps there could be some kind of metric collected whenever a player stays at an outpost for a certain amount of time. There would be certain conditions to this of course, like if they are building or mining. This new metric could give somewhat of a popularity rating to each individual outpost spawn. This new rating could then be used to send the player to the least popular one.
Hm, I think doing it randomly is a pretty good alternative! (which is what currently happens) This will make all outposts visited as often except when some people will pick a specific outpost. These outposts probably have a good reason for being picked manually, and as such it would be good for them to stay in the mix, so other players can get to know them too.