What is the best way to use a 3 flange(alcove) shower base in a corner setup?

I am having a hard time finding a quality shower base for a reasonable price. I had to settle for a base that is designed for an alcove installation.

Could there be any issues if I am installing the glass like in the picture?

Please note that the close to the viewer corner shows how the flange shows up behind the shower glass. Since I have about 3-4 inches I could build a small box and tile it and then put the shower on top of it.

The problem that I am seeing here is in the left side corner near the wall.
The flange on the right side could create an unwanted space there.

To addres @isherwood’s comment with the base possibly open on one the sides where the flanges are here is a cross section from their documentation
I also think that the manufacturer would risk to build structural weakness if the shower pane does not have a full edge side (ie it would be hollow on the sides as the drop in tubs are) This is from their manual

And here is the right side view of the base from the US manual. Hmm that might be a section. However based on the cross section I do not see how they can leave that in the air

The description of my shower says solid surface -not sure what that means but I don’t think it is like this one