Customise iOS build app with additional Xcode frameworks

I built an iOS app with meteor build. I want to customise this app by adding a few classes and Xcode frameworks.
I am able to add classes using the cordoba-build-override tree structure. But how to add the Xcode frameworks required by the classes. If I add these to iso.json it gives linker error.
When adding these classes and frameworks manually in Xcode the app works fine.

How do I add the required Xcode frameworks into meteor build ?

For iOS meteor build the cordova-build-override tree structure adds the classes in .meteor/local/cordova-build but the classes are actually not included in the Xcode project. They are not included in the file project.pbxproj and they don’t show up when the project is opened with Xcode…

Is this a bug in meteor-build or something wrong?

Unfortunately, there is currently no easy way to customize the generated Xcode project. You can make changes to the project manually, but these can be overwritten at any time.

For now this works quite well: