ahaha yeah..

A shader with a fresnel alpha please?

The fresnel alpha would be 100% transparent near the center, and the same opaqueness on the edges. So you'd only see the effect on the edges of the bubble no matter how you turn the camera.

Example on the middle and bottom.
One part of the fresnel is the reflection, the other part just a diffuse.
But instead imagine the reflection part is the current shield effect and the grey diffuse part is completely transparent.

The fresnel measures the angle of the camera. More dead on(the center of a sphere) and you get channel 1, steeper angle and get channel 2.

It would be perfect imo and help the stacking a lot!