Thank Amicus.
I bought their Nylon strum after auditioning quite a few as it seems to be the most flexible I found for that kind of work. I looked at OTS Modern Nylon, Indiginus Renaxxance, Amplesound AGL (good but nearly 3 times the price). I have quite a few realistic sounding Nylon Guitar libraries and it was mainly the IE strum engine that appealed in this case.
I really like UJAM VG Silk but it doesn't work properly in CbB/Sonar. It either crackles when loaded as a normal VSTi or works for a while and then stops outputting audio when loaded via Jbridge (a workaround which somebody else pointed out). I had started recording VG-Silk parts in Studio One (where it works fine) and then exporting to audio for import into CbB but TBH it's a bit of a nuisance!