EZiniT .

Are the identical geometries with different masks all at identical positions, if so:

Maybe you can have a setup where each object has the same mask name, you could then combine the geometry together
into a master using a fuse node and use the "output attributes and groups" functionality to bring together
the attributes from each using whatever "output values" need calculating.

I would use a visibility node, select what you do/don't want to see, then work on the rest.

The remove back faces is ok for viewport use though it doesn't remove the ability
to select points/edges of the faces it's removed (see attached)

Tint changes the default colour of back facing geometry to see them clearer

Using "shaded modes" viewport options works well with "select visible geometry only" and stops you from
selecting anything that isn't directly visible, no surprises there....but wont work with wireframe modes,
even hidden line invisible when selecting points.


Visibility node keeps what is hidden until needed again and just stops you selecting what is
not visible/hidden no nonsense nice and simple.

Edit:

If you need a quick way of selecting front or back facing primitives to hide or whatever, right
click the "geometry select" icon on the left of the viewport or CTRL+SHIFT+B. (primitives ONLY)

Could you share your setup, hip file?
Personally I have used POP force with MPM many times and never had any errors like this.