When using it, it seems to just make things more transparent, and if we apply the gradient over and over again, we eventually end up with 0 alpha everywhere.

When I first saw that mode, I thought it would blend the primary color with itself, with 255 alpha vs 0 alpha, so doing it over and over would make the picture more like the primary color, instead of more transparent.

Also, when we do it with Blending: Overwrite, we get some artifacts when alpha goes to zero:

The Transparent mode ends up being very confusing and I'm not sure if it behaves as intended or if this behavior is some bug or not, even in Normal Blending.