My observation is that the Va seems to move a bit faster on iu claims in general. I’m new to the system, so I could be wrong, but it makes sense since that initial claims have a higher bar. The iu supplemental has a high bar as well, but at least they’ve already “presumed” (their word presumptive) that the disability is service connected.
it is not a given, of course, by a long shot But it does seem at least to move faster. Yours was very fast, my iu was filed on nov 10 and c&p was on 18 December. Not too shabby. If it sails, I suspect a decision by Apr or May. But...that could very well be a denial as well!
good luck to you, watch the anxiety levels. They tend to rise appreciably at this point!