On my single, I've been running a pair of Michelin Pro2 700x23c single for a year now, which is amazing since I used to burn through Vredesteins in a month or two. Also, not 1 flat the entire time and no tread or sidewall cuts. I'm only mentioning this as background to my choice for our current tandem tires.

On the tandem with skinny Tx2 road rims, we just started using a set of new (really old stock) Michelin Pro2 700x25c. Max PSI for these foldable (no wire bead) tires is a seemingly low 7 bars (approx 102psi) stamped on the sidewalls and I think 116psi on the packaging. I'm running them at 105psi and that seems ample for us at 270lb team weight. The ride is super plush and cornering infinitely better compared to the higher max pressure Conti Gatorskins we used to have. Tires installed using only my thumbs and elbow grease.

BTW, the Michelin Pro3 700x25c can be had from Amazon for just over $32ea, shipped free. I ordered a bunch. These are one generation behind the current Pro4 version and the price reflects that. I haven't used the Pro3 yet, so we'll eventually see how that goes. Obviously these are not tires for loaded touring, and heavy loads, etc.

I had inquired about the max psi rating for the Tx2 road rims and heard back that they "don't have a PSI limit rating" - whatever that infers. I think maybe whatever the max psi a clincher tire or rims strips are rated to handle.