This is not the purpose of the add-on. It’s for Eevee settings only (with the one exception).
There is no option to disable normal maps in the Eevee settings or just the material preview.
“Disable Normal Maps” (or something like that) is a potential option for the material preview/look dev mode. This could also be under Properties > Render > Simplify, too. You can make a proposal in https://blender.community/c/rightclickselect/.
Here is a little workaround hack script, that might be useful for you. But be careful! It changes ALL materials and just toggles normal map nodes like Bump, Normal Map, etc. on or off!
Toggles mute of all normal map nodes in all materials.
Use with caution! This alters ALL materials!
NORMAL_MAP_NODES = ['BUMP', 'BEVEL', 'NORMAL_MAP', 'DISPLACEMENT']
for mat in bpy.data.materials:
for node in mat.node_tree.nodes:
if node.type in NORMAL_MAP_NODES:
node.mute = not node.mute
Do you mean under Properties > Textures (Mapping > Crop, Sampling > Filter Type)?