Well, friends, I tried the trick puting Mini-2 propellers in Spark mount, and unfortunately, practically did not get any advantages of that. The hovering time in a room with Mini-2 propellers was 13 minutes 26 seconds, and I received 12 minutes 45 with original Spark propellers. Thus, with Mini-2 propellers, I have got 41 sec more flight time, which corresponds to 5.4 % , but it may be within the measurement error and the difference in
batteries, as I used two different, but very similar
batteries. As for the noise, I measured it using an application on another smartphone and it showed that the original propellers were quieter in 2-3 dB. While hovering with Mini-2 propellers I noticed that the RPM is about 1000 higher, it's average 12600 vs 11600 with Spark propellers. I also tested Mini-2 propellers in a real flight similar to an average ordinary flight. And I also did not notice an increase in the flight time.
I want to say that it's not too easy to put the propellers from Mini-2 in the Spark mount. You need tools and skills. Most difficult is to precisely trim the propeller hub to make it fit the Spark mount. It took me several hours to complete all that. Anyway, after this mod the balancing of the propeller becomes worse, and I noticed, that Spark is hovering more unstable with it. Also, you cannot be sure of his reliability, so it's an additional risk of losing the drone.
