Configuration Views (webform) skipping 'sequence' config items

Problem/Motivation

I'm trying to filter Webforms via Category (categories in the schema)

Any config item where its type is 'sequence' is not available to the View fields selection

Not sure if its just Webform related but I would expect these to show (or can we confirm that they shouldnt and start a patch?)

Steps to reproduce

1. Make a new view with Config > Webform
2. Search for any field that is a sequence in fields - they do not appear