I've had correspondence with Fons, including a little drama about somebody improving upon his code, which he disagreed, and caused the deletion of the improved repo. This incident put me further away from working with its codebase, in fear of further retaliation from His part. If you have further interest in modelling, Modartt also has a modelled Pipe Organ now apart from Pianoteq. In the future I plan to work on GAN-based Pipe modelling, to obtain a whole new experimentation domain regarding Pipe voicing.