I know of two ways in Usine to do this:
1. Move the element on the VST GUI then the parameter inlet should show up in the patch edit window. This works for almost all parameters but unfortunately not the ones I need (browser scroll in the VSTi) because these apparently don't sent back to the host.
2. "Show all params" button on the VST GUI.
It seems to me that Usine may not show ALL available parameters when doing this ?
Here's a pic:

I've connected a textbox to the "params names" outlet and it can be seen that there are more parameters available than shown.
I've also found the paramter list page but this also doesn't seem to completely show all available parameters ? (I didn't find a scrollbar or similar).

So so far I've not found out a way to access the VST paramters not shown, is there a way ?
And also, slightly related to this, I noticed that when "Show all params" is enabled and I try to patch from a VST inlet the parameter list page seems to get in the way because it suddenly pops up and hides the patch window..
This seems to stop the patching flow a little or am I doing something wrong ?
Here's a screencapture (animated gif):

