Honestly, I love it when my snakes yawn, because that gives me a chance to see inside their mouth (without a struggle), & besides, they look sorta goofy when they do it, but I don't see any of my snakes yawning very often. Then again, I have 19 to keep track of, & I'm not watching them 24/7 either- they're not all in the same room either. Frequent yawning might just be a quirk of this particular snake, so as long as no real symptoms of a problem (like an RI) are being seen, I wouldn't "lose any sleep" over this.