We did notice in our visit to Petawawa that some of the peer support workers were actually doing this on a volunteer basis as part of an ongoing program, and no doubt assisting in their own recovery by having something specific to contribute to their fellow serving members. But it occurs to me that this is obviously a valuable part of the recovery process for individuals.
You say it can't be done within the military because of the universality of service rule, but it could be a post-employment job.