How to distribute custom importers and processors

We have many projects based on XNA in our company and they all use custom importers and processors. Currently we ship those as NuGet packages and that works great in XNA content projects. Unfortunately the Monogame pipeline is slightly different and does not support NuGet dependencies.

How would I go about adding custom importers/processors using NuGet to a large set of content projects? My thought was that I could add the dlls in a NuGet that is referenced in the game. I would then have to manually edit all the .mcgb files to update all the /reference, which is a lot of work with the amount of projects we have.

Is there an easy way to ship custom importers and processors in a library?

You can use Nuget, actually. You can have a separate pipeline csproj which builds nugets and copies them all over t the output directory. Then you reference them in your mgcb file.
I have an example here:
It doesn’t use nugets directly, but you can easily reference them and everything will work.

Plus, the repo I linked solves this problem: