Using Python to run a preset for an add-on

I want to use Python to run an add-on

Something like:
import bpy
bpy.ops.export_mesh.paper_model()

I also want to use a preset for the add-on.
Something like:
bpy.ops.script.execute_preset(filepath="/Users/paulmmxx/Library/Application Support/Blender/3.3/scripts/presets/operator/export_mesh.paper_model/psg3.py", menu_idname="WM_MT_operator_presets")

Two or three questions (please)
How does Python cope with the space in the filepath (Application Support)? I could, of course, change the name of the folder, but Blender does not seem to have a problem with the space.

How do I call the add-on and use the preset at the same time? If I run one line at a time, it fails before I get to the second line.

Something like (but it does not work):

import bpy
bpy.ops.export_mesh.paper_model(filepath="/Users/paulmmxx/Library/Application Support/Blender/3.3/scripts/presets/operator/export_mesh.paper_model/psg3.py, menu_idname="WM_MT_operator_presets")

Or, is there a way to enter the code from the preset item by item, something like this:
import bpy
bpy.ops.export_mesh.paper_model(bpy.context.active_operator.page_size_preset = 'A3')