I didn't know that Filmon just hit a major growth spurt. For me, that is actually super encouraging in terms of his development. First off, he grew up having to work with a tiny frame, so he was already disadvantaged early on but still shined and was able to put up numbers to get drafted to the WHL. Then, adding 7 inches and maybe 40 pounds to that frame and wow that's a player.
This was actually one of the big reasons I loved Jack Quinn. He was a highly undersized player up until he was 16-17, where he shot up like 6 inches in one year to be 6'0''. He only lifted his first weight when he was 17 IIRC and I kept saying that he had so much room to grow because he was only just starting to get used to his much larger body and was pretty much working with the same skillset he had at like 5'7" while being 6'0" with only one season of physical development. Look at him now. I'm not saying the same will happen for Filmon, but give this kid a couple of quarter pounders a day and give him time to fill out his frame and we might have a gem.