A Type Certificate is a family. Does this sound strange? Let me explain what I mean by that...
The compliance picture for a product family is not one matrix — it is a constellation of matrices. Each variant tied to a different TCDS entry, a different applicable amendment set, possibly a different set of special conditions and equivalent safety findings.
As somebody who had the privilege to bring some designs to first flight and then to approval, I know that the challenge of certifying the first model is very big. Maintaining coherence across the family as it evolves is an even bigger challenge.
A design change approved for one model may or may not be "easily transferable" to the next. The compliance basis for a derivative may reference the same CS requirements but at a different amendment. A special condition accepted for one variant may need re-examination for another because the design feature it addressed was modified or the regulations have changed. And when you are successful enough to start having modernization and options that you wish to retrofit also on older aircraft, things get even more complex.
In the OEM I know of, the family compliance picture is distributed across programme matrices built when each variant was certified and updated informally since. Nobody has a single view. This becomes expensive precisely when a new derivative is on the table. Or a complex option.
For OEM teams managing product families: how do you currently track compliance coherence across variants?