Randomize build props is a privacy option that allows randomizing all build props via a single option. This generates a random string for manufacturer, model, device, etc. to prevent device fingerprinting. It also hides the real user agent string that is sent from all web view components to servers on the internet.
Note that web browser apps do not typically use web view components, which is why the fingerprinting prevention may not work here. Please visit a page like https://amiunique.org/fp to test fingerprinting.