How to trigger NGO CodeGen via custom buildpipeline?

This is a long shot and I'm assuming/guessing things based on what I have researched.
I also know I'm pushing the limits here - but hey somebody have to do it :)

Background

The background for this is that my game supports mods and I'm currently working on adding multiplayer to my game using NGO.

So far things are going pretty good - but there is one major issue I still haven't figured out and it's a really big deal as mod creators will be very limited if I can't get this to work.

I'm using UMod to help support mods in my game (https://assetstore.unity.com/packages/tools/integration/umod-2-0-58293).
As far as I understand, it adds feature on top and around Asset Bundles.

The way UMod work is pretty nice.

As the developer of the game (me) I setup various things, like what scripts should be included in the "Mod Tools" and other settings. I then build the "Mod Tools" for my game from inside Unity. This result in a .unitypackage file.

As the mod creators (people from the community) you then open up a fresh Unity and import this .unitypackage file (Mod Tools) and get some Unity windows to create a "mod" and can then build a mod - which can include custom scripts.

The mod creator then "build mod" from a custom Unity menu made by UMod, which generates a .mod file that the game can then pick up. At least simply put - the important part here is the UMod builds the mod here. Remember that.

The problem

So, I have discovered that ClientRPCs, ServerRPCs and NetworkVariables are NOT working if a modder is using it in his custom scripts.

I have done some research that indicates (and here comes the guessing part) that NGO is doing some CodeGen at "game build time" - I guess here: https://github.com/Unity-Technologies/com.unity.netcode.gameobjects/blob/develop/com.unity.netcode.gameobjects/Editor/CodeGen/NetworkBehaviourILPP.cs

I'm guessing that it doesn't work, because this CodeGen is not happening on the custom scripts in the mod when it's build by UMod.

UMod supports custom BuildProcessors to run custom code when building the mods like this:
using System.Collections.Generic;
using UMod.BuildEngine;
using UMod.BuildPipeline;
using UMod.BuildPipeline.Build;
using UMod.Shared.Resources;
using UnityEngine;

// Add a build processor for script assets since we are only interested in scripts that will be compiled by uMod.
// High priority means that it will run after script compilation so build assemblies collection will already be filled out with compiled assemblies.
[UModBuildProcessor(".cs", 1000, true)]
public class PatchAssembliesExample : BuildEngineProcessor
{
    // Methods
    // Called by the build engine just after compilation if the mod includes any script content, passing all script assets as a parameter (Not interested in those).
    public override void ProcessAssetBatch(BuildContext context, IEnumerable<BuildPipelineAsset> assets)
    {
        // get assemblies
        ModAssemblyEntry[] entries = context.BuildAssemblies.Assemblies;

        // Patch all
        foreach(ModAssemblyEntry entry in entries)
        {
            PatchAssembly(context, entry);
        }
    }

    private void PatchAssembly(BuildContext context, ModAssemblyEntry entry)
    {
        // Name info
        string asmName = entry.AssemblyName;

        // Get assembly image - loadable by 'Assembly.Load'
        byte[] asmImage = entry.AssemblyImage;


        // TODO - Run custom patcher code


        // Get the patched result
        byte[] asmImagePatched = ...;

        // Check for patched
        if (asmImagePatched != null)
        {
            // Remove original assembly
            context.BuildAssemblies.RemoveFromBuild(entry);

            // Register new assembly
            if (context.BuildAssemblies.RegisterAssemblyForBuild(asmImagePatched, true) == false)
                Debug.LogWarning("Failed to register patches assembly for build! : " + asmName);
        }
    }
}

So, here comes the million dollar question that will make the sky the limits for modders of my game - how can I trigger this CodeGen for the scripts in the mod?

Note that NGO is installed as a dependency to the Mod Tools, so NGO is installed in the mod creators Unity project.

Inizia da Editor/CodeGen/NetworkBehaviourILPP.cs e dall’esempio di UMod BuildProcessor nell’issue. Determina se NGO CodeGen può elaborare gli assembly prodotti da questa pipeline di build personalizzata e documenta un percorso di integrazione supportato o la limitazione, se non è possibile.