Seems to me there's a lot of ECM type options in the smooth and new age and world styles if you tweak or hybridise them. Especially those with a more World Music, Mystical or Classical feel rather than pop, funk etc. (eg. ANSWERS is almost an Oregon style)). The RALPH1 Christensen drummer can be used for example against the ETERNAL organ arpeggio for a John Surman/DeJohnette approximation. Useful in odd time signatures with holds and motifs in the new add on maybe. the SIRIUS style has a 'Last Train Home' vibe.

In the fusion styles there's obviously METH 80/81 and the fast even 8th jazz styles
But you can do hybrids like the CROSWIND bass and piano parts along with the METH 80/81 DeJohnette drummer.


Outside BIAB there's OddGrooves ECM midi drum edition which might have some loop-able sections and fills within a rather sloppy presentation. Not too bad but not perfect by any means.

Session Band audio loops outside of the app in a windows based DAW can be used for ECM or mid 60's post bop purposes.

XLN addictive drums has a Jazz brushes set which boasts a free-jazz preset which isn't perfect but has enough of a 'metre-less' feel to it to be useable.

Elsewhere on the net there's a transcription or direct-to-midi Abercrombie/Johnson/Erskine performance of a standard with a Scandinavian pianist which is useful source of a subtle modern jazz waltz style.