What really happens in "flapping/r-voicing" English dialects when unstressed /t/ or /d/ are preceded by /n/ (e.g. /nt/ and /nd/ in "winter, blender")? Is it a nasalized tap [ɾ̃], [nɖ], [nɾ] or just [n] with the /t, d/ dropping (winter-winner merger)?
valid question