Yes. 4.2 LTS is the minimum. MatWerk is pure Python, so the same zip installs on Windows, macOS and Linux with nothing to compile.

It cannot delete two materials as duplicates until they are proven identical by exact graph isomorphism, every RNA property walked, the node tree hashed structurally, ramps, curves and node groups compared recursively, and images matched by path and optionally by pixel content.

Analyse runs first and shows you the summary before anything is applied, and every change is written line by line to a log datablock you can read afterwards. Fake-user materials, assets, linked data and any name or prefix you list under Never Touch are excluded. Missing files are reported and never deleted.

MatWerk drives Blender's own shader preview renderer rather than shipping a second one, so nothing is written to the .blend and no background process is started. Each preview is its own render job, so Max Previews is the dial, the default is 16. Turn the feature off and the polling backs off entirely.

No. MatWerk ships no materials and no textures. It is the workflow layer over the materials you already have: picking, editing, palettes, node access, PBR generation and cleanup.

Yes. No licence key, no activation, no phoning home use it on every machine you own. MatWerk is GPL-3.0-or-later, like every Blender add-on that touches bpy.

It keeps clear of the sidebar, the toolbar and the header, so nothing it draws ends up underneath a panel, and the gap to the editor edge is a preference. Ctrl+Shift+B switches it off, and the colour and node halves can be turned off independently.