Allow high rep (up for debate what rep requirement could be, maybe 20k+) users to propose edits directly to site help centers which would be only approve-able by site mods.
Stack Exchange is about to see a major reworking of its closing system. During these changes, the idea of topicality is going to reign supreme. However, a handful of mods are going to be extremely hard-pressed to keep up with the "evolving" topicality. Not only will they be trying to keep up with all of the new custom messages users will create to close questions, and the flags and disputes that will cause, but they will then have to mold the help center to match the legitimate ones.
Allowing the community to help fill in the gap of maintaining what is considered on topic will help balance out the work of ensuring "on-topic" remains relevant. As it stands, the interface may have changed but the content feels stale (for example).