Maax Neo Corner

[ArticBooger]

Hi, planning out the install on a new shower base, the Maax Neo Angle Corner Shower. It's a fiberglass reinforced acrylic shower pan with what I would call the 'disc style base' similar to the picture shown. Install guide says not to install on wet mortar. The floor is level and the pan sits quite sturdy, but not what I would consider 100% sturdy. I've seen people install similar pans on a mortar bed and my plan was to use a mortar bed despite the instructions saying not to. Wondering if there are possible risks to consider that would warrant not using a mortar bed? Thanks!