Would a 11cm ice screw be too short for any real pro on waterfall ice?

???

Depends on the quality of the ice........

I watched a "Stubby" in testing at Black Diamond and was surprised at the holding power......

BUT always follow the first rule in ice climbing......

NEVER FALL

How true! OK, thanks!

Had a friend fall on a mixed climb....had only a 10cm with a Screamer attached...total length of fall was 15-20 feet...Screamer activated to it's fullest length...10 cm held the fall with the friend upside down looking his belayer in the eyes...so yeah, in good ice they do work..

OK cool and thanks.

I place mostly 13's and when I'm worried about bottoming out a screw I'll sink a 10.
but yeah mostly just don't fall leading ice. It's not so much that I'm worried about screws pulling, I'm worried about breaking my ankles/putting a tool through my femoral artery.

Yeah I hear ya...some 25 yrs ago one of my buds broke his ankle when he fell top roping a WI climb when one of his crampon points snagged as he fell. Not good!