Testing has been with us since the dawn of motor racing (at least until the circus organisers banned it). Ferenc Szisz was a Renault test driver, as I think was Christian Lautenschlager. Enzo Ferrari writes anecdotes of testing for the
Scuderia in the thirties expaining that some drivers' feedback was better than others.. Norman Dewis was Jaguar's test driver. But I think nearly all drivers hve participated in testing and development to a degree.
To answer the question, other drivers who are known for skills as development and testing drivers include Jack Brabham, Richie Ginther, Mario Andretti, Niki Lauda. Then there are the engineers who also drove: Piero Taruffi, Mike Parkes, and Rudolph Uhlenhaut (who I don't think ever raced). I think Mike Spence and Jim Hall also come into this category.
It's a difficult subject. Jim Clark had the reputation for being able to drive around a problem and therefore was not a good test and development driver according to some accounts. Other accounts say that Chapman recognised this and found the way to work was to call Jimmy in after about 3 laps before he had time to develop a drive-around, listen carefully to what he said, and apply his knowledge of the reason why from racing technically similar cars and make the necessary adjustments. Then there are those who could clearly explain how a car was behaving but not why, those who thought they also knew why, and those who did know. .... Then there's Ayrton Senna.
I think pretty well all professional drivers have taken part in test sessions. It might also be worth looking at those who had a reputation of being able to drive around any problems, Jim Clark as mentioned earlier, Ronnie Peterson, Gilles Villeneuve. I'm not sure about GV - although he could drive around problems (or 'drive anything' if you prefer) he also took part in testing and had a positive input to development of the car.
Finally, Enzo Ferrari had a lot of faith in Willy Mairesse as a tester - if Willy couldn't break it nobody else would ...