When you save a xlam addin it will save to a specific location in %APPDATA% folders not in \XLSSTART

I made a normal excel workbook with .xlsm ands put all the code in there, i didnt use the sheets in the workbook only modules because a xlam file is not visible in excel only in the VBA editor
I saved that .xlsm file to xlam so i always have a workbook to edit if necessary

just try something and you will see what the benefits are compared to a normal workbook