Ha - I'm going to say the opposite - not helpful for you really.
Mine dropped nap cold turkey at 31 months (we did try some capped and NNDs prior to that but they didn't suit him so it was long nap until cold turkey drop). Initially we had night (10hr 10.5 hr) plus nap (1.5hr or 2hr) equals new night length, so roughly 11.5hrs night. After not long went up to 12hr night. About 5 months later though he needed an earlier BT to allow a bit more night sleep. The OT was gradual, showed as a bit grouchy in the evening, the odd micro nap in the car of 5 mins or so, EWs around 5am ish and random late WUs in the morning (like 7.30 or 8am) which he has never before done. So, rather than random micro naps, random mood and random early or late mornings we have moved BT earlier. He's now doing more like 12hr 15 nights. We keep trying to get him to bed earlier to allow for a 12.5hr night but we are pretty useless at getting dinner and bath etc done early enough.
WU 6.45am
BT aim for 6.15pm but tends to end up 6.30pm
Even the extra 15 mins night seems to help, but I think he'd do better with the 12.5hr tbh.
If you feel in your gut it's UT then go for the later BT but stick with it like MJ&N says, no point moving for a couple of days then moving it earlier again, you need to give time to settle into it.
If it doesn't work out then try going back to an earlier BT.