The addon has been rewritten and renamed to Plumber!

Comparison to io_import_vmf 0.6.9

Improvements

Major performance increases: typical VMF map import time reduced from 5-30 minutes to 2-30 seconds.
Manual game configuration no longer required: the addon automatically detects installed Source games on Steam.
No longer depends on other addons to import models: a built-in MDL importer has been implemented.
No longer caches anything on disk.
MacOS support in addition to Windows and Linux.

MDL importer with animation support.
Game file browser: easily import MDL/VMT files straight from game files without manual extraction, or extract any files/folders.
Option to remove animations or animations and armatures from dynamic props to prevent problems when exporting maps outside Blender.
Option to merge solids into one mesh object per brush.
Option to import unknown VMF entities as empty objects.
Support for 4WayBlend materials.
Support for $layertint1 and $layertint2 parameters in materials.
Support for Vindictus props.
Fixed brushes being smooth shaded in Blender 3.6 (made brushes look wrong)

Switched to custom VDF (Valve KeyValues) parser, which fixes the current parsing issues.
Game files are no longer indexed, and are instead searched for on-demand, leading to better performance.
Importer is now multithreaded.
Importer backend and Blender glue code are now separated, possibly allowing reusing the backend for other projects.
Mostly written in Rust for better performance.

Changed default import settings: texture format back to PNG and brushes back to separated