Well then, here's a stupid thought: how about IWM gets into the plastic business? No, I'm not expecting them to invest in million-dollar injection machines. But they could have them manufactured in China and brand them as IWM, or come up with another brand name. Then the customers get the pieces they want and nobody has to go rejiggering contracts.
Presumably they could. Other US and EU based miniatures manufacturers have done so.
On the other hand, they have shown no real interest in doing so up until now. What's more, I doubt Battletech is the main bread winner over at IWM. They don't share sales data, but the few numbers they do let slip (such as the ridiculously low sales rate it took to get a mold kicked into the archives 5-6 years ago), it paints a picture of a huge number of
very slow selling products, which is not the kind of thing that works best in plastic.
<conjecture>Based on that, and what I know about the hobby minis manufacturing industry, I would speculate that IWM probably keeps the lights on primarily as a contract casting shop, and maintains the metal BT line as a mildly profitable side business. If we assume that I'm even close on that, the economics of plastic will simply never make sense for the product line as a whole.
</conjecture>Now, having said that, could IWM pick out the 20 most popular items and issue them as plastics which still make money? Maybe. I definitely don't know enough to determine that. I would say that Battletech is probably a small enough market, that they would have to pick carefully, and go to great pains not to accidentally split the plastic market with CGL in a way that leaves them both deep in the red.