Both mean the same thing. "Does not prove interesting" is just more concise.
proves uninteresting is even more succinct.

I think only "does not prove to be interesting" works. The other is not correct to my AE ears.

This could be an AE/BE difference, since Captain Flint is in the UK.

I think that the verb "prove" in "does not prove interesting" feels transitive to me. So if someone said this, I would want to ask: WHAT did the measurement fail to prove interesting?

When the "to be" is put in, it is clear that the measurement did not prove (itself -- reflexive) to be interesting.

Thank you BrettUSA.
Hm, for me the emphasis on whether the measurement of ....(a method) is 'uninteresting' is supposed to be on the ones who evaluate stress responses. I don't see the difference with transitive and reflexive here, or do you mean that the measurement in general did not prove interesting itself by When the "to be" is put in, it is clear that the measurement did not prove (itself -- reflexive) to be interesting.
?

#1: Both mean the same thing. "Does not prove interesting" is just more concise.

Agree.