IQ Panel 4 not connecting to Smartthings hub as a secondary Z-wave controller

I keep an eye out to see if there are any updates that will fix this problem

Nothing specific has been listed in recent firmware updates. Patch notes can be found here for the IQ Panel 4.

but I guess I am the only one who wants to use the IQ Panel 4 as a secondary controller.

You arent the only user who is interested in this pairing and we have passed this information to Qolsys in the past.