In most of the place it works. But when I open url bar in Opera mini ( may be same in uc browser), the long press 'paste button' won't work. Though if I type something there and select it, then usual clipboard menu appears and I can access clipboard page from there but not when url bar is empty.
This will make single click open the clipboard and will work everywhere,and long clicking pastes. However the places that long clicking doesn't currently work will stay that way .
So in your case you would only be able to paste from the clipboard in opera . (Was it clear ?)