Needs more roaches, then it will perfect = )
Just to save you or anyone reading a little cash, I know those zoomed rheostats often sell for upwards to $20-25 at pet stores. You can just use a simple lamp dimmer (rheostat) picked up from a hardware store like Lowes or Home Depot. They sell them for $8-10 or so. I know it was discussed in another thread, but heat tape is also a very economical option due to overall cost and electrical consumption - approximately one square foot only uses about 12 watts and will peak out at 120 degrees F. The UTH's work great though as well!
You may end up playing around with the humidity factor as your roach colony grows, seasonal changes, etc. If you are noticing improper molts, increase the humidity by adding another bottle or keeping a larger constant supply of water crystals available. Being in the garage, they will be subjected to more humidity changes throughout the year as well as temperatures; just keep an eye on condensation buildup and the molts. Too dry - inability to molt properly. Too damp - you'll notice hypopigmentation. If you start getting condensation buildup on the sides and top, its likely too damp and you'll start seeing roaches that appear light orange and red in coloration. These roaches are more delicate due to the negative effect of their molting; same thing can happen to those who are injured during a molt. Furthermore, as the colony grows and a greater rate of respiration is achieved, you'll have less need for supplemental humidity. Your setup looks great, just wanted to give a little tidbit in case you notice any of these issues so you know the proper means to correct it over time.
It's my experience that B. dubia and those in the Blaberus genus like to be crammed together; so removing a few egg flats might have been a good call. You should have enough in there where every roach can hide out of view when disturbed, and it still looks fairly cluttered with em on the insides of the flats. Not so much that they are swimming through each other to get from point A to point B though ; )
Congrats on getting a setup to work out for inside the garage! I know this will be a valuable resource to many who only have this as an option, be it due to parental or spouse rules... I've actually had a younger customer ask me to mark "Beetles" on a package due to their parent's phobia lol!