ศาลาชุมนุม

[r2d2]

The dictionary is showing how 'got to' might be heard, and people have to learn that we merge words together but we don't write them like that.

Your innoavative and progressive interpratation of an OED entry deserves full respect.

May I give a more common and conservative in spite:

Pronunciation: /ˈgɒtə/
contraction
informal

have got a: I gotta licence
have got to: you gotta be careful

(written) gotta is an informal contraction of either 'have got a' or 'have got to". If it leaves the mouth it is /ˈgɒtə/.

It is standard (British) English (OED), and if you don't write the contraction, simply learn to do so in appropriate instances.

Otherwise, I agree with you that "I gotta go now', expanded 'I have got a go now' or 'I have got to go now', is not entirely in accordance with English grammar, or in accordance with English grammar but difficult to understand.

[Tgeezer]

The dictionary is showing how 'got to' might be heard, and people have to learn that we merge words together but we don't write them like that.

Your innoavative and progressive interpratation of an OED entry deserves full respect.

May I give a more common and conservative in spite:

Pronunciation: /ˈgɒtə/
contraction
informal

have got a: I gotta licence
have got to: you gotta be careful

(written) gotta is an informal contraction of either 'have got a' or 'have got to". If it leaves the mouth it is /ˈgɒtə/.

It is standard (British) English (OED), and if you don't write the contraction, simply learn to do so in appropriate instances.

It is not standard, it is colloquial, actually, vernacular in my view, how it got in the OED is beyond me. But then I am not clever.
I certainly do not intend to use it, there being no appropriate instance when I should.

[r2d2]

Beggar's last words: ผมจะไปแล้ว I gotta gonna

[Pirin]

What did he say to me?

This is just an informative statement telling you that the writer was going to leave.