Before I say anything, how would you characterize your soil? Is it more like sand, more like clay, or something in between? Is water penetration an issue for you? Have you ever done a jar test?

Definitely more like clay, very dense. The guy who aerated my yard last fall said it was about the worst he's seen in terms of straight up clay. Until this spring I always had lots of pooling after significant rainfall, then rock hard after it finally dried up. This year I have way more grass than any previous year and I applied Aerify Plus in the spring. The pooling of water is much improved (but still happened during heavy rains we had in May) - but it does drain in hours instead of days like previous years.

My soil is likely calcreous, limestone quarry a few miles away - bump.

While you're waiting for dchall :

My soil is likely calcreous...

With a pH in the 8's, low Sodium levels and abundant Ca levels, that would be a pretty safe call. :)

You're fine having tested at 6" if you included the soil from a slice that includes all the soil from the surface down to that 6" level. The reason 0" down to 4" is preferred is that the majority of turf roots are in that top 4" of soil. Therefore, it's more important to know what nutrients are available in that section than 6" or 10" or 24" despite that turf roots can reach those depths. Besides, surface applied amending is going to take a long time to leach down to those deeper levels and calculated application rates would create massive excesses in the shallow soil depths.

So, did your soil sample reflect all the soil from the surface down to 6" or just the soil at that 6" level?

It was all the soil from 0-6" in thin vertical slices from many locations around the yard.

Kudos, then no big deal at all with going 6" dchall should be on eventually.

Hmmm... maybe Becky will show some "mercy" (inside joke-sorry) and help you out until dchall surfaces again when its safe. :/