longName:LongNamedo little for you in most diagrams (except when displaying information about participation in derived property queries such as Requirements relationship queries):
Most of the time, the Type is completely adequate in communicating the role of the instance-level element it types.
And even if your instance-level elements do have names, showing them in diagrams does not always communicate useful information. This includes especially part property and port symbols.
What about SysML value properties with a ValueType? Yep, often you can completely get away without a name, and if you can, I recommend it. Note also that the ISO-80000 libraries even have specific definitions for concepts such as 'length' and 'diameter', so you can even get away with using the Type for those in many cases.
If, however, there are multiple instance-level elements with the same type but clearly different roles, you may wish to distinguish them with unique names, but even then, make it concise!