I think that if you're really concerned about this, stick with regular Dvorak. It's available pretty much everywhere without installing anything. For Colemak,

I think that if you're really concerned about this, stick with regular Dvorak. It's available pretty much everywhere without installing anything. For Colemak, it's on every Linux distro and the Android stock keyboard from 4.0+. It's easily installable on Windows. I don't know about the current status on Mac and iOS.