Let me explain what i am trying to achieve.

We have items bought and sold either in Pounds or in Pieces as Unit of measure.

Occasionally we buy an items in pounds but sell in pieces or vice versa.

the big problem is when we setup a Unit of measure , we have to set the generic formula up.

So as an example when I create a Unit type called Weight, it has these lines- LB as base, MTON with conversion rate as 2204 * LB. Likewise I can add more lines as long as i know the conversion rate. But these are global conversion rates.

This cannot work for our system because each item has its own Pieces to pounds conversion rate.

Hence I have created client side scripts on the Sales order to mimic what we were trying to achieve.

The only reason I asked this question is because someone had Suiteworld 2017 mentioned that we should look into catch weight and I was wondering if it was an add on module. Sounds like from what you are saying, the Regular 'units' drop down on a Sales order already functions like Catch weight.