he needs a training to prepare himself for the renewal SEP skill test.
So what value is there flying solo for this event? Whilst not illegal, there is no requirement. With regard to claiming such a flight towards the 25 supervised solo flights, there is nothing that says what flights they should be however; the clear intention is that to be meaningful, they should be ab-initio flights.
As such a flight now has to be conducted at an ATO (or RF) surely they will have some say regarding the suitability of a solo consolidation flight!