At my company we design skylight systems that use multiple parts in an assembly, and each piece has its own number, qty, length and location:
eg. Frame left A01
Frame right A02
and so on.
It seems that the only thing i cannot link is the qty (see attached pic). Is there an easy way to do this or do i need to just deal with entering the qty manually based on my BOM?
If qty is going to be a static value that will always be the same regardless of where it's used, you could add a custom iProperty to that component that you could then pull in to your note just like the other iProperties you are currently using.
If that qty is variable, you could make the component an iPart and only change that Custom iProperty value for the variations then just make sure to select the right one for insertion in to your assembly -or- just do as you are now and enter them manually.
Although probably not what you want, this is the role of the Parts List on the drawing. It details the items used in the assembly.