WebView2 performance optimization: Seeking best practices for flag usage in real-world browser app

[nirdil]

Hi everyone,

I've been doing deep performance profiling using the BrowserBench Speedometer benchmark.

To explore tuning options, I tested a variety of WEBVIEW2_ADDITIONAL_BROWSER_ARGUMENTS, including:

--disable-features=msSmartScreenProtection,msWebView2EnableTrackingPrevention,msWebView2EnableShoppingFeatures,msWebView2EnableFamilySafety
--disable-background-timer-throttling
--disable-renderer-backgrounding
--disable-backgrounding-occluded-windows
--no-first-run
--msWebView2CodeCache
--js-flags=--scavenger_max_new_space_capacity_mb=8

However, Speedometer scores remain largely unchanged, even in isolated test environments. Would appreciate guidance on whether this is the right approach, or if there's anything else I could try to improve runtime performance in this context.

Would appreciate these clarifications:

1. Which of these flags are actually respected in WebView2 (specifically in WinUI 2 vs. WinUI 3), and are there any additional relevant Microsoft-specific flags?
2. Are msSmartScreenProtection and msWebView2EnableTrackingPrevention considered officially supported flags to disable for scenarios like incognito browsing or performance tuning?
3. Are there any additional WebView2-specific settings or APIs or DevToolProtocol commands, beyond startup flags, that are recommend for improving Speedometer scores?

Thanks,
--Niro