[Infamous90]

Going to do a WIR for a non-amazon yet big company. (It's hard to use search because of the 3 character WIR).
2 questions: 
I'm guessing I should order within a day, but not within 10min of eachother?
Is it okay that one of the orders has multiple items, as to increase the weight of the package to match the other? Of might this complicate things?
(both boxes will contain a very similar heavy item tho)

Just checking so I don't miss anything obvious.

I would suggest you to visit the store (if they have any close by) and check out the size and weight with the packages. I even bought my own scale once to the store and weighted both packages so I know how much the item weighted with the package. One of the sellers noticed me and I made up an excuse "trying to stay within luggage weight limit for my flight", and we both laughed about it lol.