When we use OPL instruments and want to use effects (vst or directX) we cannot apply singular effects to specific OPL instruments - the ways around it at the moment I personally employ are :
1 either group a bunch of effects at the top of my effects bus and make them all master, and they then apply to every opl instrument and inevitably when I use sampled instruments I can send them out to some kind of hopefully a vst that doesnt effect the sample at all (for the clean sound, to just bypass all the mastered effects right at the top) or
2 render the opl to a sample and lose some of that wonderful rendered on the fly goodness of the opl.

If we could apply vsts to individual opls (theoretically in the same way we do to other instruments, in the sinstrument tab) then none of this has to happen and we would have a lot more flexiblity.

PS - if this request has already been submitted, I did search but didnt find it, so I hope that I dont upset anyone.