How does the new WW ias work?

Now that WW using ias from all gear, does the ias from your primary weapon count towards your secondary? For example, if I had a botd cb in the main hand with highlords and Death cb off hand, will I be able to hit the max 4 frames for both?

apparently not
27 ias for 5 frames
75 ias for 4 frames
https://warren1001.github.io/IAS_Calculator/

I'm not really certain of the new WW mechanics so take this with a grain of salt but unless they completely deviated from the normal design of multi-weapon scenarios in general, the answer should be no.

No because generally speaking, when you look at having more than 2 weapons, "primary attack stats" (bit of a generalization/lack of a better term there) only apply for each one particular weapon. That's things like attack speed, crushing blow and so forth. They won't benefit anything done with the respective other weapon.
"Secondary stats" on the other hand, such as resistances or stat points on a second weapon, do apply at all times.

From what I can gather (largely based on how the warren calc works with it), each weapon is treated independently, using the IAS on that weapon and any off-weapon IAS you may have (but not the IAS on the other weapon) to determine the speed for each weapon. Your overall WW speed is then the rounded up average between the two.

Its all very confusing. Macrobioboi put out a video when the change first happened.

At the 530 mark he says you can have slow off hand doesnt matter if you have a fast main hand. However, all the calculators that Ive used say different.

Seeing how he immediately follows that with saying it'll take smarter people than him to explain why that may be, I wouldn't put too much trust in that particular statement.

Even more so since he later in the vid says he basically has no idea about IAS breakpoints and needs.
Quote: "I'm not the person who is able to crunch those types of numbers".