@Felix-W Break it down. Make a minimal project with one sampler where notes only trigger during legato transitions. Once you get that working you can start to incorporate it into your project.
@dannytaurus Good job detective!
I agree to the WTF, seems that developing new protocols of all sorts but there's still no agreement whatsoever in the way DAWs handle such a simple task... Shame...
There is a detailed comparison of various pitch algorithms.
Rubberband performs really well and it's not too difficult to integrate into Hise.
I think there's even a detailed post somewhere here on the forum about this topic.