It's not the clown knife that you need to worry about. If the 13" RTC has a 2" mouth, in my opinion it will stretch out to at least 3-4" when it it trying to swallow something down whole. There are no bones in the fleshy cheeks and corners of their mouth that would limit the elasticity/stretchability of its jaws. Example.... Let's say that your mouth is 2" wide with it shut and relaxed. Now open it upas wide as you can. Now grab your cheeks at the corner of your open mouth with a couple of fingers and stretch it as far as you can. Your 2" mouth just stretched out to 4-5" easily and you don't normally swallow things whole while eating as a RTC would. Their mouths are made to stretch out and inhale everything regarded as food. Sometimes they try to eat another fish and its too big too swallow down its throat and into the stomach, but that doesn't stop it from inhaling the fish even if it dies trying to swallow it. Too big for the
throat is often an easier fit for it's larger stretchable pie hole. I know you have probably thought about it over and over. All you can do is wait and see. There are some extremely smart fishgeeks on this site. IMO, they've been in your shoes, you know been there done that. I believe that they just don't want someone to make the same mistake as they did. Heck, they got the pictures proving their point. RTC are swimming mouths with a voracious appetite and sooner or later, ODDS ARE you're gonna hear that first splash one night that wakes you up just like I mentioned before. Nothing is set in stone though. You might be the 1 in 1000 that gets away with growing everything to adulthood together without a problem. Not likely, but still a chance. All you can do is your best and pray to the God of Hemioliopterus .