Alrighty, I'll try again.
First off, generally a child is not waking 12+ times per night unless there's some pain or discomfort involved - is he on any reflux meds? If so, when was the dosage last checked? Any rash or other skin conditions?
Having said that, I do think there are some things we can do to help him sleep better. At 6mo, average A times are 2:45-3hr and most babies are at least moving towards dropping the nap - alert sprited babies are often already on 2 naps with 3hr A times. This is probably why he's protesting when you pop him into bed for a nap at 2-2:15 A time and why he's only napping an undertired nap of 45min. Lots of these short naps can lead to OT at BT, so that's probably part of why he's crying so much at bedtime. It appears from what you've written that he *can* sleep 1hr at times, so from that I surmise he can transition from one sleep cycle to the next but mainly towards the end of the day when he's tired enough.
I think if you stick with a routine like this for 3-4 day at least, note the actual EAS and we can tweak from that:
WU
A=2:45-3hr
nap
A=2:45-3hr (can do 2:30 if short nap)
nap
A=2:45-3hr (can do 2:30 if short nap)
BT (or catnap of ~30mins followed by 1:45-2hr A to BT if you need to lengthen the day)
Ideally, you're shooting for a day of 12-13hr and a night of 11-12hr.
With respect to feeding a reflux baby, they just do need to be fed more often if they can't eat a large milk meal as other babies can. We advise against feeding to sleep but if he's not able to take more than 3oz at a time, he clearly needs to be fed more often in a 24hr period so he can get enough food in to grow and not be hungry. Whilst you are not offering solid food, maybe trying feeding another milk feed when you'd offer solids (generally an hour after the main milk feed when he wakes). There are some great tips on the FAQ section of this board:
https://babywhispererforums.com/index.php?board=13.0. You are also welcome to post there for more reflux-specific info.
WRT CIO - we don't support that here. No judgement, you were likely at the end of your tether but we won't suggest it to you, nor will we support you through doing CIO. We will suggest more gentle sleep training methods in which you *teach* your baby how to relax into sleep. For now, I'd suggest using shush/pat in combination with those much longer A times I described above and see how you go with that. It may annoy him, so have a play around with what works. The idea is to provide two things for LO to concentrate on, physical touch and audio so they can relax. If that means holding your hand on LO's chest whilst singing a song, that's fine.
That's a fair bit of info, perhaps start with that and we can keep working through things along the way.