Further, most escorts have the ability to run 2 copies of tac abilities anyway, with room for only 1 copy of A2B, which will not double anything.
So if you would be so kind, please support your "double healing and double attacking" assertion with the details of your build.
Several escorts can indeed use 2xA2B. The Armitage, Mobius, and Blockade runner come to mind. There must be more I can't think off the top of my head.
While the boff powers are not "doubled" it does make for some interesting builds. My own Mobius for example uses only one copy of CRF1 and BO1 while having constant uptime of APD/APO. Is it better than keeping with a more traditional all DHC DCE + AP doff setup? I'm not sure TBH. I was wanting to find a way to use the flashy new Chroniton DBB more than anything else lol. But it does have its healing boff powers available more often, even if they heal a little less.