Mjölner, Cyclone and breakpoints

Greetings exiles!

I haven't been able to find any information regarding the breakpoints for Mjolner with cyclone. There's plenty of information about Cast on crit (which i am NOT), or the information I found is from when Mjolners internal cooldown apparently was 150 ms.

At 250 ms internal cooldown, the optimal number of attacks per second with a shield is obviously just below 4. But if you add cooldown reduction, is it a linear progression or (i.e 6% cdr = max 4.24 aps, 12% cdr = 4.48 aps) or are there certain threshhold values needed to be met, with anything in between having no effect? I know that's how it works for awakened cast on crit.

Thanks a lot!