How to Query Features (Epics) with all closed Jira issues, except for one specified project?

[Steven Johnson]

Using JQL how can I write a query that returns - for my project "LMNOP" - Features that have closed Jira associated issues, but exclude one specified project from the return?

I found this query which covers the first part of my question, but doesn't include an exclusion:

statusCategory != Done AND issueFunction in epicsOf("issueFunction in issuesInEpics("project = LMNOP")") AND NOT issueFunction in epicsOf("issueFunction in issuesInEpics("project = LMNOP") and statusCategory != Done")

I cannot figure out how to get the same return if I exclude one project from the return.

Essentially, I have a Feature that contains 2 projects and I only want to know when a Feature's issues are all completed with the one project, while the other can still have an issue(s) open?

Any help would be greatly appreciated!

I have tried to add a "AND project != QRSTV" in a few places around and within the query, but I'm really just missing the logical piece, so I don't even know if that is what needs to be added to make this query work how I want it to.