Too many words punishes your mistakes
When I choose dictionary/language, I'm pretty much choosing between US and UK English. I choose UK because I'm in South Africa. The trouble first of all is that the UK version includes all the UK town names, and secondly that lots of scientific and international terms are thrown in too.
While it sounds like a nice idea to have a very big dictionary, the actual fact is that it works against you, because if you don't swipe/flow exactly, you're getting given a weird UK town name or an Indian dish.
My suggestion is that you break the dictionaries into packages and you select which combination of packages you want.
For example, select from:
- UK English 100,000 most popular words
- UK English extended dictionary
- UK place names
- UK English scientific words
I'd imagine that SwiftKey is collecting enough data to extract the most popular words and break out levels of dictionary.