Hi, BB. I do not think this is true. My reasoning is, I have heard from a GMAC video they specifically took input from Business Schools while designing GMAT Focus, where schools said they want to put more emphasis on data analytics capacity which is why they removed geometry and made DI a full fledged section. So I think DI cannot be compared to IR in terms of relevance anymore.
Schools check Q score for quant readiness.
Schools say V score is more indicative of success (Yale newsletter)
Schools advocated for DI.

:cry:
bb
Hi. If your score (overall is good for you) then the individual sections don't matter much.
It is not worth getting another 655 with a different combination of Q, V, and DI.
P.S. 78 on the DI is 69th percentile. It is not anything that would make any AdCom reconsider, esp since they did not care about the IR score (the precursor of the DI) just a few years earlier.