+ AA6YQ comments below
Reading the update notes for Commander 15.4.4 I see an undocumented feature on a Yaesu rig that wasn't ignored..
+ "Supports the undocumented FT-757GXII meter reading CAT command" in Commander 15.4.4 was low risk: that radio's functionality cannot be changed via a firmware update, and the change supports a capability that isn't already present. If it were to fail due to a future action by Yaesu, users would be in no worse shape than they were before Commander 15.4.4.
+ Icom radios provide a Split mechanism that works well for working DX stations operating split. Exploiting undocumented commands in an Icom radio that is under active development with firmware updates to replicate functionality that already exists would be risky, and would not be a good use of my development time compared to alternative uses of that time.