One thing that could vastly improve the suggestions would be to only insert a proper noun if I've first tapped the shift key. Here again, Android has the infuriating habit of suddenly inserting a person, city or country name into the most prosaic of sentences.
My other major annoyance with this kind of typing on mobile is that; once the fuckwitted algorithm has made a ridiculously wrong choice, when you spot it a word or two later and go back to correct it, all the corrections offered are variations on the wrong word it chose, rather than alternatives for what could have been chosen initially.
And the very nature of typing on mobile means you're looking at the keyboard, not what's appearing on-screen [as people can do, to various degrees, on 'real' keyboards]. So, unless you're looking up at the screen between every single word, to make sure it's correct, a lot of the correcting has to be done belatedly. So the errors tend to pile up.
And usually a misplaced duck is less harmful in a polite/business setting than a misplaced fuck.
“I saw a fuck on the road on the way to work” in work chat is a different type of embarrassment than “what the duck were you thinking you ducking idiot” in a personal text.
https://www.thedailybeast.com/the-apple-kill-list-what-your-... might be a place to start