I would lean towards the 3M stuff… I mean folks are saying 3M plugs muffle things, but look at the decibel reduction rating. The loops linked in your article are 7 decibels vs 34 decibels from the real ear plugs.

Maybe 7 is enough… But I’d say the reason 34 decibel reduction is considered muffling is because it’s a real significant reduction vs a minor reduction. Maybe you only need a minor reduction though 🤷‍♂️.