* Always at least pick the current instance, even if no others are
visible
* Only apply to VS output picking. Inputs either don't vary with inst ID
or are trivial (all verts identical) depending on the element selected
* Respect the currently selected element instead of always picking
the position output
* If we're selecting a different instance, we have to queue the vertex
selection because otherwise the refreshing of rows breaks it
baldurk
c12279f641