Custom User Fields V2 API

When utilizing users for my board application I have run into a couple of problems that can be easily resolved and would majorly improve the potential of applications.

Our main current use case for users is to utilize the fields assigned to a user to populate fields in a dynamic email footer. This could be improved by supporting custom fields added to users in a user call via API.

In the future we are hoping to use users in advanced ways like determining permissions ETC. I think looking to improve this by adding calls to update fields could be a major help to other app developers not looking to build their own app based roster.

Please let me know thoughts and concerns with this request.