I think you misunderstand the problem.
A publisher in a matrix project can work in following two phases:
- For each child build, after finishing builders of each child.
- For the parent build, after finishing all child builds.
The latter phase is supported by publishers designed for matrix projects.
Publishers that does not designed for matrix projects works only in former phases.
So, even publishers does not support matrix projects, you can use them in matrix projects and combine with Flexible Publisher.
It is not necessary to filter them out.