As it happens, I beta tested a web browser for 2.5 months in 2022, namely the Ghostery Private Browser, which used to be called the Ghostery Dawn Browser.
However, I was too excited about doing this and made the mistake of using my desktop-only main computer for the browser beta testing, which created system corruption. 
As such, I experienced instability and performance issues, which were not visible and noticeable while using the Ghostery browser, but instead, they damaged my system. 
Afterward, I ran system maintenance tools such as Deployment Image Servicing and Management (DISM), System File Checker (SFC), and CheckDisk (CHKDSK).
And SFC found integrity violations that it successfully repaired, and occasionally, I run the above tools to ensure system stability, so I deeply regret the beta testing. 
Consequently, experiencing the above is my reasoning for deciding not to beta-test the DuckDuckGo browser for Windows or any browser in the future. 
But as a Web Browser Enthusiast, I instead enjoy using my 15-16 STABLE Mozilla Firefox and Chromium-based browsers, which is reasonable. 
Good luck! 
Microsoft Windows 10 Professional 64-bit V. 22H2 (19045) Retail Desktop PC, EAMH Paid/EEK, MB 4 Prem., and Unchecky, MDFW, FF with uBO/AG, Grammarly Free, MBBG, and Acronis CPHOE (DI), SUMo Free. I have 28.5 Years of PC Experience.