metal, meddle, mettle, medal pronunciation in American English

Oxford Advanced Learner's Dictionary of Current English has the following phonetic symbols:

meddle

/ ˈmedl; ˋmɛdl/

medal

/ ˈmedl; ˋmɛdl/

mettle

/ ˈmetl; ˋmɛtl/

metal

/ ˈmetl; ˋmɛtl/

Oxford gives British English usages; in BrE, meddle and medal are pronounced the same and mettle and metal are the same too.

I know that in AmE, t is usually pronounced as d.

Then how are metal and mettle pronounced?

Are they pronounced exactly the same as medal and meddle in AmE?

Adding to my confusion: please look at how they are pronounced in Merriam-Webster.

meddle

Pronunciation: 'me-dəl

medal

Pronunciation: 'me-dəl

mettle

Pronunciation: 'me-təl

metal

Pronunciation: 'me-təl

Solution 1:

Both words are typically pronounced [ˈmɛɾl̩] with a voiced alveolar flap.

That [ɾ] which I've written there is one of several possible phonetic allophones of both the /t/ and /d/ phonemes, but doesn’t sound quite like either [t] or [d] would there. It’s a very light, quick tap — such as you might find in the middle of the Italian (or Spanish or Portuguese) word cara.

Spelling is immaterial here: all four of medal, meddle, metal, mettle typically have that same pronunciation in most speakers at normal conversation rates.