Improve keylock algorithm

I was testing out apps to slow down tempo and came across Amazing Slow downer.

I compared the quality of tempo change with DJAY.
Djay’s keylock is very noticeable compared to the apps quality.

I changed tempo by 25 BPM and experienced only a  clean sound with no audio changes.
DJAY is only good at slowing or speeding up up to 10 BPM.
I don’t know what algorithm DJAY uses, but it could be improved. Something like Pitch & time that is an additional  purchase?

Keep in mind Serato’s Pitch & Time is their tech that they developed. It was literally their claim to fame and how they started out in the business. Even before Scratch Live. Their time stretch algorithm is unmatched and to be quite blunt we probably won’t see anything like it from any other SW developer due to the fact that it is already widely used in the audio and video industry and the amount of money (R&D) that would have to go into it without even knowing if it could be possible just wouldn’t be worth the efforts. To improve it YES but to what degree? Little bit of Serato history if it interests you

Not sure what algorithm DJAY uses, but ZTX sounds very good