• Liquid Glass Toggle New option under Display & Brightness → Liquid Glass lets you switch between Clear and Tinted modes for a custom transparency effect throughout iOS 26.
• Refined Glow Effect Tapping liquid glass elements no longer brightens the entire background — Apple subtly reduced the “blow-out” effect for cleaner visuals.
• Display Zoom Preview Update Now shows the new iOS 26 wallpapers inside Display Zoom settings (though the Messages app preview still shows the old layout — a known bug).
• Apple Intelligence UI Adjustment “Beta” badge removed and title now left-aligned to match other settings sections; may signal it’s nearing public release status.
• Lock-Screen Camera Toggle A long-requested switch in Camera settings lets you disable “Swipe left to open camera” on the lock screen — no more accidental launches.
• Bug Fixes & Known Issues Fixed: devices sleeping unexpectedly while using lock-screen apps. Known: Airdrop icon visual defect and Portuguese news queries fallback to web/chat search.
• Performance & Battery Stable and fluid experience reported on iPhone 17 Pro Max (Geekbench scores ≈ 3786 single / 9742 multi). Battery life appears unchanged from beta 3.
• Next Steps RC (build 23B5073A) expected around Oct 27 → public release week of Nov 3 → then 26.2 Beta 1 and 26.0.2 bug-fix update shortly after.

This summary covers iOS 26.1 Beta 4 (October 2025) based on developer testing and public beta observations. All names and trademarks are property of their respective owners.