I don't know, I've only tried it with 6.4.2 but there shouldn't be much changes since 6.4.0 that affects the modifications. The threads part of this is basically the same as for 6.1.x for which I've run the integration for quite some time.
I've taken a quick look at the changes since 6.4.0 and I can't see anything that should affect the integration, but I can't say for sure.