[JimmyMac]

A plain black modern rubber hose and nothing else. I am using Simplifix style hoses with the indicator stripe.
Deterioration and damage is easier to spot early, particularly with fuel lines and any form of covering will prevent this.
Use ground French chalk or Talcum to look for cracks.

For me, the black Nomex would be nice if I had a regular check and refit regime.

Electrically the same applies.