I've tested some more with an old favourite of mine, Jconvolver.
At first, it came up with an error that it couldn't find jack, which was running. After scouring the interlink, i had an answer.
Most apps have a default for a jack name, and if the user enters nothing, they will, well, default to a predetermined name, usually their own.
Jconvolver doesn't do that.
So when users start the app they need to add a switch (-s) and a name (default), something like:
$ jconvolver -s default <name of your config file.conf>
Voila, jconvolver sees jack.
This has been a public service message.....