Not the best solution but can the silicon ear bud part be taken out or replaced? Some in-ear earphones can still stay in place even with the silicon part off but the sound quality might be worse and they are less securely fitted to the ears.

BIOS /UEFI malware exist too. Your suggested best practices should also factor this in. Basically if you’re being targeted there’s nothing you can do but by being aware of these risks you have a better chance to keep yourself safe.