From what I've read about breaks at the seat tube/bottom bracket junction, the failure mode is fairly benign, you probably won't completely crash & burn if it fails again. The sticky bit comes when you eventually resell it - you disclose the repair and price it accordingly, the buyer promptly "forgets" to disclose the repair and resells it for full price. There are probably some creative things you could do to reduce the likelihood of that scenario if it would weigh heavily on your conscience...