They are trying to maximize the light output for the cans. Any suggestions?
I have seen lamps explode when there was a loose/flakey neutral condition. Once is was a 60 watt A-19 in a pendant, the other time it was a G base halogen in a wall sconce. When the halogen exploded it sounded like a gunshot and took out the protective cover as well. The wall sconce had a neutral wire literally falling out of the wirenut. This was on my own house.
Is there plenty of free air space around those 4" cans? As far as I know there is not an IC rated 4" remodel can made.