Vermouth has been released in version v2.5.0.

After version 2.4.0, there are now global launch options for Proton, Wine, Native, UZDOOM and Steam. Proton games get a “Join running container” option and launch considerably faster.

New Features:

• Global launch options - Settings now includes a Global Launch Options section with fields for Proton, Wine, Native, UZDOOM and Steam. Users can input commands like gamemoderun %command% that apply to every game using that runtime. Individual game settings override these globals.
• Join running container option - Proton games gained a per-game toggle to “Join running container for this prefix,” enabling tools like trainers and mod managers to interact with already-running games in the same prefix.

Improvements:

• Performance boost - Proton games now launch considerably faster; the application no longer queries umu-launcher for existing containers on each launch, eliminating unnecessary waits and retries.
• Interface refinements - Updated labels, icons and various UI elements.
• Documentation updates - README expanded with a “Why Vermouth” section and documentation covering the new options.

Source: GitHub