You see, for this specific product we have, that's the thing we are trying to avoid.
All parts are either always the same, or are standard profiles that only change length, meaning the part complexy is very low, while the most important thing for us are the assembly drawings.
And because of that we are trying adjustable parts to avoid having dozens of parts that are basically the same with different lengths. (for example, we have 4 parts that change based on the product's heigh, and the client can choose virtually any dimension from 2300 and 3800 with a multiple of 10, meaning we would have around 150 possible dimensions for each of those parts)
Using the adjustable parts linked to global variables also saves a lot of time and reduces the risk of mistakes when people manually set values or when people forget to "Save as" (and when you work with people that are new to modelling and new in our company, those mistakes are extremely common).
Sorry my suggestions won't work for your application. When you talked about these parts being cut on a plasma, I immediately thought you have to program each different length part, so it was my common sense that you'd have unique programs for each new length, thus new part number. Your application is out of the normal to my experiences.
Best of luck, adjustable parts are good for a lot of things, but why they can't read the dimensions/variables that are adjusted, really makes zero sense to me. We fight it all the time, people forget to change occurance properties (for our situation), when they create a new length adjustable part...........