[+Dean Jackson since it's WebXR related] Hello WebKit, I'd like to ask for WebKit's position on the dynamic viewport scaling feature that's part of the WebXR API. This is intended to let applications render to a subset of the full viewport and adjust that scale on a per-frame basis if needed to reach target framerates. Specification: Part of WebXR, see for example https://immersive-web.github.io/webxr/#dom-xrview-requestviewportscale Explainer: https://github.com/immersive-web/webxr/blob/master/explainer.md#dynamic-view... TAG review request: https://github.com/w3ctag/design-reviews/issues/588 This was discussed in https://github.com/immersive-web/webxr/issues/1091 and multiple calls with the immersive-web group. The changes were merged into the main specification via https://github.com/immersive-web/webxr/pull/1132 , but to the best of my knowledge this hasn't been launched in any other browser yet. Could I get your position on this? For context, the goal is that this API is optional for UAs. It would be a valid implementation to provide a requestViewportScale method that does nothing. If it is supported, the UA can optionally provide a recommendedViewportScale numeric attribute based on internal heuristics, but it's also valid to keep that undefined. Thank you, Klaus Weidner