Found the existing en gb model for british english users. Helpful!!

[stilez]

Tested, works.

Very difficult to find if unfamiliar, so its worth adding

[ElishaAz]

How is the performance compared to the English (US) model?

[stilez]

Never tried en-us. The 2 are sufficiently different that if a model could only handle en-us it wouldn't work for me in the UK. Id spend much more time correcting it than time saved tbh.

That said on its own merits,very accurate. I like it. I have to correct as you'd expect for Sayboard - capitals, numbers, and until 4.1 punctuation but those are true for all models/languages. Apart from that, I find it very very good for British English.