FloXpress is limited to internal analysis. If you want an external analysis, you've come up with the workaround. Use a section view or "select other" to get at the lids.
For FloXpress, you're also going to get stuck on outputs, shear isn't available for FloXpress.
Overall for your problem, are you planning on modeling all of the fibers? That probably isn't going to be computationally effective. We nornally handle something like this with a porous medium but you won't learn what you want from that method.
Also, are you expecting the sheet to deform from the fluid interaction? That also is outside the realm of Flow Simulation.