I'd love a reliable alt keyboard, but for it to be useful it must be predictive past fixing typos. And that’s the sticking point for me right there. It has to gather at least some data about me, and in permitting that then I may put at risk info I’d rather not see distributed more widely. It’s hard to see how a company can actually make assurances that a “glitch” won’t happen. Even the best of apps can have "one or two"

bugs...
As far as testing any new app, I can be enthusiastic but I'm also wary. I might think I need it or want it, but what I don't need is something half-baked or misbehaving to the point of causing me to wipe my device and start over. How many times do I want to wonder if my personal data was compromised anyway?
So I maintain an extra iPod touch with an isolated username setup and only the stock iOS permanently maintained on it. When I’m interested in a new app, I download it onto that device for openers. I want to see what it asks for and how it behaves for awhile. Some apps never get past that step.
But if I like the app then I put a special throwaway mail account on my testing device and use it to surf the news sites like AP or Reuters for a while, mailing links from it to another dummy account that I have on an old iPad Mini (also having only a stock setup on it).
And so forth -- gradually widening the test device’s window on the world and checking to see how the new app behaves in assorted circumstances. If I have questions or concerns, this is the timeframe in which I ask developers questions.
If after awhile I haven’t noticed any weird behavior while using the app as well as the browser and test mail account, then I ditch the test setups, cleaning off the testing devices so they’re ready for use again sometime. LOL well it’s a way to justify having the old gear around anyway.
Final step: think whether I really need that app, and then if I like it enough, install it on my iPhone or iPad.
I'd love to have an alt keyboard that could pass that shakeout. So far? Still waiting.