TL;DR Use the load script to Change the name of the field.

Ah, figured it out. We use the master dimension so that we could have clean names for displayed above the selected filters and the use of LTrim was part of that. When the master dimensions was just the field it would not use the label but when the dimension was a formula it used the label.

Now in the load script we can load the field as "Master Dimension" and it will have a nice label when when to filter the selection.