can't tell... what is not really working? if that's an insert send/return to/from the same client instance (qtractor) than you prolly know the answer--proverbial undefined behavior.
otherwise, it's not clear what really the problem is: is it that you're sending from and then returning to different qtractor instances? and expect the audio export will work? i'm afraid you're expecting and confusing the roles of one or each instance, as for their respective outputs may now be quite independent...
know that qtractor multi-instance is only there and indulged because of NSM support; all other use cases are not really a feature and might actually behave as terribly buggy--you've been warned ;))
only the later may foster any improvement.
can't tell... what is not really working? if that's an insert send/return to/from the same client instance (qtractor) than you prolly know the answer--proverbial undefined behavior.
otherwise, it's not clear what really the problem is: is it that you're sending from and then returning to different qtractor instances? and expect the audio export will work? i'm afraid you're expecting and confusing the roles of one or each instance, as for their respective outputs may now be quite independent...
know that qtractor multi-instance is only there and indulged because of NSM support; all other use cases are not really a feature and might actually behave as terribly buggy--you've been warned ;))
so, the answer to this is..., not quite.
cheers