Yes. That annoying persistent notification is removed in all AOSP-based custom ROMs for nmol31.

When searching for "huawei nmol31 custom rom verified" , you will encounter forums like XDA Developers, 4PDA, and Telegram groups. A "verified" ROM meets these criteria:

The journey is not for the faint of heart. It costs ~$16 for an unlock, requires 2 hours of patience, and voids your warranty forever.

: Historically, the most stable option was LineageOS 14.1 (Android 7.1). While official support has ended, community-maintained builds may still exist on platforms like XDA Developers.