Choice of adhesive on akw triform - Tile Advice

[Bopster]

Hi guys, got a job next month where customer has a new extension and is supplying akw triform and membrane with linear drain. Walls are new MR plasterboard Bare no plaster tanked with mapei Tiles are 30x60 porcelain
Which would be your adhesive of choice for floor and wall
I’m trying to convince them to replace the plasterboard with wedi in the enclosure 1600x800