You’ll have to confirm all of this with webMethods tech support but I think you will be okay.
It’s been a while since I’ve looked at this but I’m pretty certain the later releases of webMethods Workflow no longer makes use of the broker to maintain state… so the question becomes, are there issues with the versioning between the latest Workflow server and Enterprise server when publishing documents directly to the broker?
Unless you’re on an extremely old version of Enterprise now (which you probably aren’t if you’re on Workflow 6.0.2), then I’m doubtful there were any changes with the API interface that might change the interaction between WF and Broker… and don’t think they’re using an unpublished api as part of a simple pub/sub exchange with the broker. Pretty much the same goes for IS.
I haven’t worked with this in a while so, as mentioned above, you should confirm with webMethods tech support before proceeding.
Hope this is helpful.