This is similar to the Inspiring Liberation exploit a while back when you were able to cast it before combat to your whole party. That was fixed but shielding touch is still castable out of combat. The fact that it stacks with itself makes it too much of an exploit to be ignored.

I still agree with this.  I know I am invoking Helig of Thein on this topic and likely no more patches will come out.  I Guess you just have to go with the Honesty badge (You are a Shieldbearer after all!) and not use it until combat starts.