Product ships in 3 - 4 separate boxes

I was just checking with UPS and the number of boxes can change the ship cost quite a bit.
Say I have a 20 lb product that ships in 3 separate boxes. UPS charges me 3 times as much when
I split into 3 boxes (depending on destination). I could just add weight to that product until I get
the price higher but that is not accurate as the prices varies so much on a heavy product depending
on destination. I know often people just try to find something in the middle and sometimes its not enough
and sometimes its a little more so it evens out. Which is fine for smaller products.

I use Q's UPS mod that allows multiple boxes but you have to choose a weight that splits the shipment.
But for this I would have to specify that every 7 lbs adds a box so that a 20lb order would get rates
for shipping with 3 boxes. Can't do that though since there a lot of products that are 10 - 20 lbs that
all use 1 box only so those would be incorrect.

So are there any mods that would allow me to add the number of UPS boxes to an individual product?
Or would it be difficult to create & may be able to hire someone to create? I assume its not that easy
since I don't see any or is just needed very often?

Only other option I know is to have customers call in these orders?

thanks!