I see, that drag delay must be something different then. If the previous Onboard version behaved better, perhaps try switching preferences->Keyboard->advanced>Input event source to GTK. Typing in firefox' URL-bar will suffer, but that's the closest thing I could imagine having an influence. Else I'll sooner or later try to reproduce it on my Nexus 7 (doesn't run Ubuntu currently) .
I see, that drag delay must be something different then. If the previous Onboard version behaved better, perhaps try switching preferences- >Keyboard- >advanced> Input event source to GTK. Typing in firefox' URL-bar will suffer, but that's the closest thing I could imagine having an influence. Else I'll sooner or later try to reproduce it on my Nexus 7 (doesn't run Ubuntu currently) .