Hi there, I'm sorry you haven't got a reply yet!
If you're quite sure he's not in discomfort anymore, which it sounds like things are going in the right direction with the reflux meds and elimination diet, I do think setting aside a couple weeks to exclusively work on getting him to sleep in the crib is a good idea. Although, it sounds like you're still getting some 20min maps, which are generally considered discomfort/pain.
As far as a plan, I'd stick with an A time of 2-2.5hr, as that's average for 5mo old. I'd keep a good log of your EASY/settling for a week and then start to look for patterns. Try to settle him for 40min at the start of each nap. If he doesn't fall asleep, get him up and do a 10-15min break and then try again for the rest of the nap time. If he does fall asleep but wakes early, try to resettle for 20-30min. If he doesn't go back to sleep, get him up and start a new cycle with a slightly shorter A time (maybe 20-30min shorter).
If he's touchy, I would actually get rid of the light show thing, as that's probably distracting/over stimulating for him. Most touchy babies like to sleep in the dark with white noise and not a lot of intervention.
As for feeding, do you have any proven reasons why you think he might not be getting enough or that he's really hungry? If he's gaining weight well and things are good on the reflux/intolerance front, I wouldn't think you have cause for worry. It is common at this age to do top-up feeds with EBF babies, as often they don't make it to 4hr between feeds until solids are started. So, you could do a big, main feed upon wake-up and then a top-up about 30min before nap time (just make sure he doesn't fall asleep nursing
).
I hope that helps... I'm not sure I answered everything for you (I'm tired myself today
), so be sure to ask other questions if you have them.