Tdv8 200 mile trip today, intermittent stuttering on the motorway, 75mph ish. Car was warm and on one occasion the revs were oscillating 2/300 revs. Hard acceleration cleared the issue, but the issue persisted, with no explanation of repetition

There is a software update available that may cure this. I had it on my 4.4 TDV8 especially on cruise, but no where near the rev figures you have. Mine was a mere 'hunting' like a miniature to & fro'ing. Local Indy used the software update below & all seems ok.
If you look back through the posts on here, somebody also mentioned this a few months back, hope this helps.

Land Rover software: LTB 00454V2 2012 Orkney Grey Westminster 4.4TDV8 with Ivory interior.........nice!
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