SSE (Server-Sent Events) would be a game-changer for ProcessWires core, and the trash functionality example perfectly illustrates why:
The Current Problem: As you mentioned, the current trash system is painful - deleting hundreds of pages requires multiple confirmations, long waits, and often timeouts. Your clients shouldn't need API knowledge just to empty their trash efficiently.
How SSE Solves This:
One-click bulk operations: Start deleting 1000+ pages with a single confirmation
Real-time progress: "Deleting page 234 of 1000..." instead of a frozen screen
No more timeouts: SSE keeps the connection alive, bypassing PHP execution limits
Graceful interruption: Users can safely stop/pause operations if needed
Beyond Trash - Core Benefits:
I have written several converter or importer modules for my clients, that import data and transform them into pages or a payment matcher module, which compares bank statements with invoice pages inside of ProcessWire. For all of these modules I wrote custom SSE Event handlers myself which is much boilerplate and duplicated code as Bernhard mentioned.
Imagine every ProcessWire installation having this built-in:
Import/export operations with live feedback
Batch page operations (move, publish, unpublish)
Asset processing (image optimization, file management)
Search index rebuilding
Module installations and updates
Why Core Integration Matters:
Standardized approach: All modules can use the same SSE implementation
Better UX across the board: Every long-running operation becomes transparent
Developer-friendly: No need to reinvent the wheel for each module
Professional feel: Matches modern user expectations from enterprise CMS
Addressing Adoption Concerns: I can't predict what percentage of users would use this feature - nobody can provide statistics for something that doesn't exist yet. But consider this: every ProcessWire user who has ever dealt with timeouts, batch operations, or large imports would benefit immediately. The feature would be invisible to those who don't need it, while being invaluable to those who do.
Your modules already prove SSE works brilliantly with ProcessWire. Making it core functionality would elevate the entire ecosystem.