Cannot Load Unsigned CEP 12 Extensions in Premiere Pro 25 on macOS 15 — PlayerDebugMode Ignored

I am unable to load any unsigned CEP 12 extensions (custom panels or test panels) in Premiere Pro 2025 (version 25.2.3) on macOS Sequoia 15.1, despite correctly setting PlayerDebugMode as described in all Adobe documentation.

• Extensions are placed in both /Library/Application Support/Adobe/CEP/extensions/ and ~/Library/Application Support/Adobe/CEP/extensions/

• defaults write com.adobe.CSXS.12 PlayerDebugMode 1 is set and verified

• Both Premiere and the system have been restarted multiple times

• CEP12-PPRO.log shows no mention of the unsigned extensions—not even errors or skipped loading

• The issue is reproducible on a clean install of macOS and Premiere Pro on a second Mac

Is there a new, required process or debug flag for loading unsigned CEP 12 extensions in Premiere Pro 25.x on macOS 15? Has PlayerDebugMode support been changed, deprecated, or intentionally removed for CEP development on this version?

This issue is blocking all extension development and testing on the latest version. Please advise if there is a new recommended workflow, workaround, or if this is a known bug.

Thank you.