Do you know of any RFs operating out of unlicensed airfields?
There are situations where the use of unlicensed fields is necessary, for example if somene is being taught strip flying. The main point here is that the student already has a licence and is not being taught something for the grant of a licence or rating.
Checkouts or conversion training comes into the same category. Someone learning on a new type within an existing class rating that they hold would not need to use a licensed a/d.
The issue of licensed airfields for instruction is under consideration by the authoiry, particluarly in respect of the need for fire cover.