Hmmm, he's talking about epoxying the seatpost into the seat-tube so as to not require any tension from the binder-bolt. However, that will still not solve the geometry problem. Which is that the weight-loads on the forward-positioned seat creates a torque on the post which bends it forward and causes A LOT of stress in a direction not in-line with the tubing. That bending-forward post is what most likely caused the crack over time. The ultimate solution is to have a bike with +80 degree seat-tube to allow the centre of the seat to be directly above the hole in the seat-tube. In which case, there won't be any bending moments.

For how, you want to get a STIFF seatpost (alloy or steel) that fits VERY tightly and far DOWN inside the seat-tube. So something with 4mm+ wall-thickness, like an SR Laprade or similarly beefy post. Then make sure it's at least 6" down into seat-tube. With that much contact surface-area, any 2-part epoxy will hold easily.