Has anyone had problems with their pool caused by not having patio blocks supporting each column?

I read somewhere (possibly from HRDennis?) that patio blocks are needed on corners if your base material is very sturdy like hardpan (clay+rock mixture).

We've got very solid undisturbed hardpan soil and I am getting really tired of digging just the towers down. We have a 12'x24'x54" Diamond Star (Wilbar) if that makes any difference. I'll do it if people confirm it is important or if nobody has enough experience with missing patio blocks to make an informed opinion.

I'm starting with just the 4 corner towers in case I get some good news .