If you desperately need a previous firmware version and the e-fuse prevents downgrade, the only hardware-level solution is to replace the with one that has an older firmware.
A one-toggle "downgrade" that strips away modern bloatware, heavy UI animations, and automated content suggestions to return the TV to a high-performance, minimalist state. 1. Interface Simplified Static Home Screen: Replaces the dynamic Samsung Tv Downgrade
Updates can introduce bugs that break Wi-Fi connectivity, cause screen flickering, or create HDMI eARC audio dropouts. If you desperately need a previous firmware version