Hello Stig
First, a drawing of the plane from mid - 1937 :
At this date, according to local newspapers, technical drawings were about complete, a wind tunnel model had been built, and the plane itself was "under way" (understand some wood has been cut...). So the wind tunnel tests were done with a model.
Then, why this plane ? As you say rightfully, not for technical reasons, despite the fact that qualified designers from Loire-Nieuport (SNCAO at this date) were leading the design team. The answer has to be searched on the political side.
At this date (1936-1937), the French government came from the left wing (Front Populaire), and the Air minister (Pierre Cot) had introduced the Aviation Populaire (people's aviation) with two purposes : allowing the working class to fly light planes (and not only the wealthy class), and give the opportunity to young people to train as pilots, proficient enough for advanced training later by the Armée de l'Air. Both objectives were only partially achieved, for a lot of reasons.
So, if the "proletarians" will learn how to fly, if the training plane has proletarian origins it would be perfect... And since the design team of the CAPRN 10 came from a "Aviation Populaire" group, full circle was closed.
But, in April 1938 the Front Populaire government exited, and such rethorics were not longer needed. The planes for the Aviation Populaire were purchased mainly by Salmson and Caudron (who had not the needed industrial capacity at this time) and the CAPRN 10 plane was only built in two exemplars : one to be destroyed on the static tests, and our F-AROR.
Regards
Jean