Bud
Yes, NFR = New Feature Request
In Linux you can do whatever can be coded. Some things are less difficult, some more difficult. It becomes a case of how much cost or effort is required to achieve a desired end result, and whether that effort is practical to carry out.
Your request is a good one, but someone will have to do the coding. Either the original author of the user manager or someone else may be prepared to code. If not, you will need to pay someone to do the coding, assuming there is an acceptable cost/outcome ratio.
You should submit a NFR at bugzilla against the contrib category (if it exists).
For now your only option is to not allow that user to have access to the Users panel.
On the other hand, if you are allowing that user to control the sme server, surely they can be trusted not to tamper with your or the admin users passwords ?