The jump to version 5.1 is a game-changer because it officially supports UEFI booting GPT partitioning
For those without a current license, ArcaOS 5.1 must be purchased directly from Arca Noae or authorized resellers like Bitwise Works . Pricing for ArcaOS 5.1 - Arca Noae
Have you tried running ArcaOS 5.1? Let us know in the comments if you got it working on modern hardware—or if you finally gave up and moved to eComStation.
Regarding the request for a it is important to note that ArcaOS is a commercial product. There is no official free version, trial, or demonstration ISO available for download. ArcaOS 5.1: Key Features & Modern Support
Released as a major update, ArcaOS 5.1 introduced several modern capabilities for OS/2-based systems: