I think the utility mastery tree will gain a huge boost if the final upgrade is an increase to the max CDR a champion can have. Currently CDR is capped at 40%. I recommend that the final upgrade would increase the cap to 45% or 50% (depending on what balances best).
What does everyone think?
For this to work, it would have to be near the bottom of the support tree, and even then it could cause some serious balance issues.
For example, having a support 
with a 25 second ult would be hilarious/terrifying. Also, CDR is important enough on a number of characters that going full 21 on the support tree would be something I can see a lot of people doing just because it's so strong. It would make 
have a 100% uptime shield, 5 seconds till it goes away, 5 seconds until it's up again, and that's just "traditional" supports.
Looking at other characters, the cooldowns would be hilarious, but I did love URF, so idk.
