No conventions are needed because a Feature Table can point, via its FeatureParams field, at a specific name ID. See the feature tag registry which also mentions which name IDs may be used.
No idea where we stand in the implementation of descriptive names for Stylistic Sets in applications.
But here's a question anyway:
As far as I know there are no specs on where in the naming tables to put them. Any name table ID can be chosen.
Here I also see a major reason why no one bothers to implement them because they don't know where to look.
Are there any conventions yet on ID ranges?