If anyone is interested in getting more info on stomatpods, I find this a while back. Best site for identifying stomatopods and learning. The author's name is Roy Caldwell. I actually emailed him a while back and he responded. I remember asking him about lights and burrow sizes with peacock mantis shrimps. He said there is no case of bright light (LEDs/bright t5's) affecting O. Scyllarus and giving them shell rot at SMALL sizes, but as they get bigger (around 5-6 inches) there are multiple cases of this bright light being a factor in the death of O. Scyllarus species. Also, if you use PVC for a burrow, I remember him saying that they will only use it if it's at least 1.5x the diameter of the mantis' body, and at least 4x the length.
When I had my peacocks, I did an experiment where I switched the t-8 fixtures with marineland LED fixtures. After the switch, the mantis shrimps wouldn't come out at all until night time, even to eat. I changed the lights back after a week, and they resumed normal behavior and cruised around all day and night. This was only for O. Scyllarus.
Hope this helps some people! I cant wait to get my new baby mantis!