Adding second brood box and maybe I goofed Olea's

I decided to add a second brood box to all three hives yesterday.  The guidelines are to add when 80% of the frames have drawn comb and are covered with bees.  I had started the hives with drawn comb on all frames, and there were about seven frames covered.  We're going away next week, so now is the time to add boxes.  The frames in these boxes are either new or used and scraped.
As usual, a seeming simple task turned complicated.  The added box did not fit snugly onto #3.

Large gap between boxes

The top box would rock.  At first I thought it might be a problem with the added box, so I tried another- still not snug.  I scraped the edges of the bottom box to no avail.  I felt this gap was too much, about 1/4 inch.  As I pondered various solutions (duct tape), I put the boxes on the other hives.  Then onto the internet where I found this discussion.  Lots of ideas.
I gathered popsicle sticks, duct tape, box cutter (to shave shims) and a cinder block and returned to the hive.  The box would rock, like a wobbly table, so I could not figure how a shim would help.  I put the cinder block on and it made a significant but inadequate difference.  So I scavenged more weight.

This brought the boxes together, and no need for duct tape.  Of course, it will be added work when it comes time to go into this hive.

With weight on top

Yesterday morning I took at the entrance of Olea's to see how many bees the MAQs had killed.  There was a bunch on the porch, as expected, but there was also a cluster on the front wall.

I looked through the window and the combs around the MAQs were devoid of bees.  I feared that the fumes were too strong due to insufficient ventilation, so I cracked open the top.

You can see the edges of the bars and spacers.  There is a bit of a gap between the last bar and the back of the box.
The cluster has gone back into the hive, but the combs around the strips are still bee-less.  That means that the brood on those combs has no nurse bees and is likely to die.  Who knows what other damage was done?  My intentions were good and perhaps things will turn out well.  We will know in a month.