The biggest problem I see with this is practicality. I'm sure there is some way to bond multiple of the same spren type, but if you're going to bond a second spren, why not get a spren that gives you a whole new set of surges, instead of one which the only new thing you get is a second blade, which you could get with any Nahel bond other than a Bondsmith.
As I said, considering the way which investiture works, it is almost guaranteed that there is some way to bond two of the same type of spren, but I personally would rather have two different spren, even if two of the same would give me some level of extra power in those respective surges.