>>16730524
https://x.com/torybruno/status/1351606858134528001
>Atlas has ogive SRB fairings to lessen aero loads on the aft end. This also means that the separation is briefly delayed in order to get a clean sep, causing a very minor performance hit. Vulcan does not have this constraint and will use conical fairings, with sep at SRB burnout

I also remember him saying that they were originally planning to have pointy boosters on the Atlas V, but I've got no clue how to find that specific comment. The GEMs and Castors that were used previously all were pointy, so I guess that'd be expected.