Hi.
I just layed down a travertine tumbled pavers 1 1/4 thick pool deck in Florida.
My PB graded the area lowering the deck about 4" below the coping line.
A method they use is to waterjet around the pool specifically where all the plumbing lines were installed. Simply this process is sticking a hose in a long pvc buried in the clay/sand we have as ground here in Tampa Bay. This process compacts the deck, kinda like the sand near the water on the beach...it literally will drop your deck a few inches where the trenches will be dug up.
Based on our weather the installation process is to lay 3 to 4" of crushed concrete, it is then tampered and smoothed out.
90% of paving contractors here in florida will at this point lay the pavers right on top, 10% will add a little portland cement into the crushed concrete base.
All perimeter joints are bonded with portland cement. Afterwards they basically throw sand all over the joints and brush them in...
On my covered lanai, they simply put down sand and layed them right on top...
I know it sounds like do they move easily? Not at all---some may make noise, this is a result of the leveling on that stone.. but its solid

I would not lay concrete down-what is the additional cost for this?
It will crack it always does...you'll have to replace the stone and pavers around.
the method above if a stone gets dirty/cracks etc...you can take a scraper loosen up the joints and pop them out, not that easy though.
This of course are the inside perimeter stones...
We are at the point whether or not to seal them, leaning on yes to bring out the color and add a sharkskin mix to prevent my little ones from wiping out. It's slippery when wet, especially barefoot...
Hope that helps, any questions lemme know...ohh and make sure you account for at least 10% extra on your sq footage...
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Oops, one more thing...
My pool builder was charging between 10-12 a foot with materials...
I became the sub on this cause I layed about 1600 sq ft.
They did not have any issues, only that they will do the pool coping which is commonplace.
So by doing the deck myself, I bought good quality select grade travertine pavers and hired my own contractor...
Came out great and saved thousands of dollars....
I'll let you know where to send me a check for this tip
