That sounds so useful. I've wanted that so many times! In practice, I end up manually typing in long URLs on my laptop that people send me over SMS or whateve

That sounds so useful. I've wanted that so many times! In practice, I end up manually typing in long URLs on my laptop that people send me over SMS or whatever, and manually typing in long, high-entropy passwords on my phone when I would rather copy-paste them from my laptop's password database. (Not that I'm running KDE. But the feature sounds great.)