>>87774829To be honest it doesn't look to be a real "dialect", both because it's otherwise unattested, and also because it's just a more or less 1 to 1 sound replacement scheme applied to more or less standard Japanese, and this is important, including its assimilations and contractions. It's important because assimilations and contractions present in a natural dialect are contingent on the nature of the phones present.
The resulting vowel system is extremely unstable, and the consonants have too many places of articulation present which would be bound to level off were it a real dialect.
I don't know enough about speech impediments in terms of phonology so can't comment on that.