> I'm typing this on a swiping keyboard. It's different enough that a better layout might have been worth it here...

Perhaps, but as someone who has been proficient in QWERTY, Dvorak, and Colemak, and who now uses Colemak-DH I can say that I leave my phone and small tablet keyboards on QWERTY.

The separation of common letters in QWERTY forces your finger to move farther when swiping, but that provides a bit more distinguishing information for identifying words. When I tried swiping with Colemak and Dvorak my finger basically scrubbed back and forth across the home row and words were often mis-identified.

There are slightly improved swiping input methods like 8pen, Typewise, Hero, etc but if you are entering enough text to be able to amortize their learning costs you might be better off getting a portable Bluetooth keyboard or just using voice dictation.

Same here. I adopted Dvorak as a youth, so when I got my first smartphone I put the keyboard in Dvorak.

That only lasted a few days for two reasons:

1) What you said about the mistakes. It is so much easier to fat finger in a way that makes autocorrect clueless.

2) The muscle memory doesn't translate at all anyway. Obvious in retrospect, but typing with your thumbs is a completely unrelated skill to touch typing. Turns out both live separately and equally in my brain.