Display Custom Field Types in Meta-Box Builder (missing hook)

I have created multiple Custom Field Types for a customer (https://docs.metabox.io/custom-field-type/). But I am not able to figure out how to integrate these new Field-Types to be displayed in Meta-Box Builder GUI.
As far as I was able to figure it out, there is missing a hook to registert Custom Field Types for meta-box-builder.

I beliefe a hook would be neccessary in file: meta-box-builder/src/helpers.php function mbb_get_builder_menu()