Frame Challenge: We don't need to separate mod and CM use of status tags - instead, we should be more discerning in how we apply certain status tags.
Status tags can be loosely grouped into two categories: "final" and "transitional".
The recent CM Community Asks push, which saw massive CM activity on cross-site metas, only updated uses of transitional tags. Most notably on MSU, was the removal of status-planned from tag cleanups. Note that questions with [status-completed] and [tag-cleanup-request] were not touched, for example.
Thus, in my opinion:
1. Continue to use 'Final' tags freely
They aren't interfering with ongoing CM work, they allow us to mark stuff as 'done', and they help to filter out completed or declined requests with ease.
2. Use 'Transitional' tags only in specific circumstances
There are occasions where mods adding status-planned etc are useful, but probably the most likely use case is when you are simply keeping local bug/feature request posts up to date, when the topic of that post has received a staff response elsewhere e.g. on MSE or MSO, or in a Mod Chat room (and the staff have explicitly stated they're ok with an update being made public!).
For example, I added status-planned to Can the review queues respect ignored tags? Arqade, after seeing it applied to Review Queues and Ignored Tags Meta SE.
Note: status-review is a special egg that allows us to raise a post for CM review. So continuing to use that one for that purpose is obvious.
3. We don't need to group by "planned" anyway.
If we are vigilant in applying Final tags, then anything without those tags can be considered as fair game to be considered, worked on, updated, and so on. Filters, like the one I linked earlier, can be used to the same effect as a dedicated 'planned' tag, but with the added benefit of not accidentally excluding ones where status-planned was never added. This might require a bit of cleanup on the mod's behalf.
If something requires action but the question and discussion doesn't make it clear: put what needs to happen in an answer, and update that answer with any stats or other updates as you go.