This is why I like having discussions... I could never get a chance to bounce ideas off someone else about improvements. Having slotted boxing was a normal thing for bonuses and just wait until you try to make a build to solo the MoLGTF. This build can't solo the LGTF so my dual build is stone mastery for Seismic Smash and the heal to fight the weakened hamidon. The green mitos required brawl, boxing and seismic smash, no joke.
Anyways, I tried out the build you suggested and found only one problem. When the dmg proc in the hold doesn't go off, it's 20 less dmg and 40 under containment loss and the loss for poisonous ray is only 9 without proc so that one isn't so bad. It could be pretty good overall, survival wise, if you put the last two slots into health and put the panacea proc and the preventive medicine proc in. Those two have saved my blaster countless times.
Do not put panacea into conductive aura since it is used offensively for end draining groups. Also an end mod could be put into static field to help with end drain too. I use both to drain multiple groups at once to minimize issues. The computer during the ITF is a good place to set up 3 static fields to take care of all of the robots and end drain them.
I see that this build loses a lot of accuracy overall, 20%, but it shouldn't be too much of a problem if you're not fighting 54's or something.
I wouldn't drop fly unless you don't care about a travel power and I definitely wouldn't drop it for focused accuracy. That thing is and end hog and you wouldn't be able to slot it well enough. I suppose that the build up proc could be put into tactics as well but eh.