I just used Karn emblam to finish off a guy using Sheoldred and mulitple Midnight clocks. 3 clicks per one damage was P-A-I-N-F-U-L for both of us (he had 74 life at this point). I would rather have been offered "How much damage?" "Ok tap 5 artifacts" hit Sheoldred, then count up and face damage the other 18. Then Paradox Engine a 0 cost artifact creature to untap all, face damage another 20 or so (repeat til dead and he couldn't see my hand to show lethal).

Yeah it works for me, but if you want to do 4 damage why can't you just click it and then tap 4 artifacts? You end up having to click - tap click - tap 4 times and the whole while you are getting roped for using time.

I initially thought this was an issue. I came back to say this works. You have to click on the actual emblem and then tap an artifact.