True, I actually meant to add a "if it works for you though..." in there. I'm just saying that I suspect you're having trouble with your throwing technique more than anything. (I've noticed that a surprising number of guys who actually have flown a number of contests still have lousy lauching technique, and can get in to real trouble in a tailwind or strong crosswind situation). But it's not the plane, it's the guy throwing it. (and you don't have to be an olympic spear chucker to get a good lauch, I'm sure not).

As for the fuel foaming, I have no idea about the rount tank, it might work. But I'd look at getting a little foam around the tank first, unless you have the round tank already. Getting a round tank mounted well could be an issue as well, you don't want it flying off the first time you slap wings with someone. But I've seen several guys with round tanks, usually in the .25 classes, so I don't think there's any reason not to use one.

Also, are you actually getting air bubbles in the line between the tank and the needle, and did you rule out pinholes in the lines and do a pressure check of the system? Sometimes pinholes can be really hard to find, and nearly impossible to see.