gntry wrote:

The manufacture suggests setting the new acrylic shower pan in a bed of
cement to add support I guess. My question I hope not that stupid, Is
something like a mortar mix better than cement mix? would I use a "stiff"
mix and just trowel it out so the pan "seat" itself? Anything better then
using cement? Expanding foam?

I like "cement". Actually what is called a "sand mix".
Mortar mix will crumble when it's in a big lump like this.
Sand mix is stronger than mortar and without the giant stones in
"concrete".

You want the mix on the mushy side without being watery.

Trowel the mix onto the flooring and then squish the pan into it.
If you misjudge and have too much mix to allow the pan to sit
properly, take it up and remove some mix. Use a level to confirm the
pan is correctly set.

Jim