Will Kaspa increase posterity header density in the current KIP?

No — the current KIP recommends keeping posterity headers at their existing density and deferring any hourly-storage change to a separate follow-up proposal. The proposal explains that decoupling posterity headers from pruning headers would grow the header size to 312 bytes and would be harder to implement than the rest of the KIP combined. There is also an open question about whether the extra pointer might eventually be removed entirely if the pruning mechanism can piggyback on posterity blocks without additional computational cost. Knowing this helps set expectations: the optimization is on Kaspa's roadmap, but the developers chose a staged approach — ship a working design first, then revisit density only if demand and necessity justify it.