There is no reason to think multihit ws would get the bonus w/o a triple attack proc. if some testing shows otherwise, which none I hve seen has, then it would be safe to think it works that way. I do not see why anyone would think or tell you it would work on ws without a triple proc. Even then I would assume it would only modify the 2 extra hits of the proc and not the main ws at all. I would think it is even more likely it doesn't work on ws at all, but that is just my opinion.
And I fail too see a situation where using it for to over a haste belt would ever be worth it. 7% haste is a lot to give up for a what 5%? (made up number I am on my phone and cannot check that quickly) bonus to only TAs... It's a good dex belt, and last I checked cheap. Its great for SA and the dex ws but for tp I just can't see it being worth it on any setup for any situation.
99 THF, COR, DRK, BLM, WHM, DNC