Hello,
Since riot put in "Athene's Unholy Grail" I've inserted into alot of my builds. however with the extra CDR I usually go over the cap by 4% due to also wanting the "arcane knowledge" mastery and being forced to take the "Sorcery" mastery.

Though I would still take "Sorcery" on some champs right now it feels more like dead weight and useless mastery points on most of my builds than anything else.

Thanks,

So because you changed your build in place of an optional item, Riot has to change their mastery because it doesn't suit you?

Ryze likes it as is. 4% from offense, 6% from Utility or 8.1% from Defense (2.1% over doesn't matter much to me) + Q passive for 10% + Frozen heart 20%.

You don't go over the 40% mark until late-mid to early-late game. At that point, masteries don't really help much as they are mainly designed for early game.

I'd still rather not have that extra 4% and have another start bonus

Then don't take it. Pretty simple fix.

10% MPen doesn't make or break anything, void staff exists.

Well then don't choose those masteries...
The bottom line is, that 4% CDR will help you for the first 20-30mins of the game...
That's usually 75% of the game...
You're complaining that 4% CDR doesn't help you during... What... The last 10mins of the game?
It's a small sacrifice to make, considering how much that 4% CDR helps for the rest of the game, early game is far more important anyway...

You don't HAVE to take that mastery, or that item...
It just happens that taking both has a VERY MILD DRAWBACK...

It's like taking Sunfire Cape, and then complaining that you agro'd a jungle mob while fleeing and died...
SunFire Cape has a VERY MILD DRAWBACK in some situations... It doesn't make it a bad item, it just means you very rarely have to be slightly more careful than usual...