Proper string gauge for Super Concerts

I've built two super concert ukes over the last couple of years, and I've kept both strung with Aquila Tenor strings. I figured the tenor gauge strings were the proper match for the tenor scale on the ukes. They both play and sound great, but one of them (cherry) has developed a slight bellying behind the bridge and a very slight sinking between the bridge and the sound hole. It hasn't changed the action at all, and appears to have stabilized. My tops are 1.6mm (.063") and are fan braced with 1.6mm bridge plates.

Anyhow, I recently purchased a Kanile'a super concert and it was strung with concert gauge Worth clears. It just got me wondering if I should be using concert string sets on these ukes due to the concert sized bodies. My first inclination would be to think that it wouldn't matter, as a concert body is smaller and should have less unsupported top surface area than a tenor, with the bridge closer to the tail block. If I stay with tenor strings, should I look for lower tension brands, or maybe tune down a half step?

Anyhow, I don't know if this really matters, but I'd be interested in any responses. As for sound and feel, I prefer the tenor strings.

My hunch is that is has more to do with the way you built the uke than it does tension from the tenor strings. I'll often use tenor strings on my concerts because most concert sets seem under powered to me. Did you incorporate a radius in your top? Is your bridge plate over sized" How tall are your braces between the lower transverse brace and the saddle position?

Chuck, my ukes have flat tops, bridge plates that match the bridge lengthwise and are about 1/8" wider front and back and the brace is around 3/8" high between the lower transverse brace and the saddle position

Put a 15' radius in the top and I'll bet you'll eliminate the problem of the top distorting.