As I have stated in more current threads, my 2014.5 Lounge refrigerator has NO bottom venting and very poor top venting. I can't get it under 44 on hot days and it is still February.
I just ordered a grille to replace the 3" high board below the drawer beneath the microwave. The vent is a marine part that will take some southern engineering to fit, but it should be attractive when I am done. I'm also considering an additional vent on the aft end of the galley cabinet between the folding counter extension and the wall, probably using a 3" furnace register.
I have piles of 12v
muffin fans of all sizes in my shop. If the vents don't do the job, I'll pull the box out and install one of my fans following the Novakool drawings. I can fabricate whatever mounting parts I may need. I would use the taps that Novakool supplies for fan power, but I would also wire a switch in series to kill the fan when not needed.