No that is incorrect. Like I said the MORE attack speed applies LAST in the damage calculation hence why it is theoretically 602.4 with 20% more attack speed.

As an example: If you have for a prismatic eclipse with 3 green sockets you would have 36% increased global attack speed + potentially attack speed modifiers on your tree that would apply BEFORE the 20% MORE attack speed that is on the gem. The MORE attack speed modifier will ALWAYS be applied last hence why it is a 602.4 pdps shield with 20% more attack speed.

It works no differently than the berserker node aspect of carnage where the MORE damage is applied as a 1.4X multiplier last, except in this case it is tagged directly to attack speed so it is tagged to apply to your attack speed last. Since it is tagged to apply as a multiplier after global modifiers from the tree as another ADDITIONAL SOURCE OF DAMAGE it is not part of the weapons base damage but moreso seen as an additional line of text on the weapon itself. 602.4 pdps shield with the tag 20% more attack speed. Imagine a shaper mod that just stated 20% more attack speed on your 602.4 pdps weapon.

The tag MORE is always applied last hence why the base theoretical dmg isn't 722.88 you have to calculate modifiers on your tree / gear that would affect your weapon or in this case shield before multiplying them (in this case by 1.2 since it's 20% MORE attack speed).

You can't just give your base weapon 20% more damage (in this case attack speed) then add additional attack speed on afterwards you would be losing out on the multiplication of the more attack speed of those additional sources of global damage that should come before hand. you would actually be losing damage in that case or do you intend to multiply a second time by 1.2 which would be ludicrous just giving you a bigger number for no reason?

The comparison to ice crash is just to help understand the difference of more damage modifiers but since it seemed to be too confusing I figured perhaps aspect of carnage might be more straight forward as it's not about the attack speed modifiers but the increases and decreases in global modifiers preceding MORE modifiers.

That being said GGG did confirm that the base phys damage will increased with levels with their latest post on their website, so while the base damage is 602.4 with 20% more attack speed at the moment it could be higher at 20/21+.