There is possibly an easier way. I found this when trying to work out how to remove the scales defigned in mm.
The Scales are stored in the registry.
Windows Registry Editor Version 5.00
[HKEY_USERS\S-1-5-21-2599018305-3156215502-2470237774-3769\Software\Autodesk\AutoCAD\R20.0\ACAD-E000:409\Scale List]
" 0.ScaleName"="1\" = 1\""
" 0.ScalePaperUnits"="1.00000000"
" 0.ScaleDrawingUnits"="0.08333333"
" 0.ScaleType"="3"
" 1.ScaleName"="1\" = 5'"
" 1.ScalePaperUnits"="1.00000000"
" 1.ScaleDrawingUnits"="5.00000000"
" 1.ScaleType"="2"
The above is metric but you can reword accordingly. Note it is version specific (R20.0\ACAD-E000:409)
Now when I run scalelistedit reset it defaults as my reg key.
Please don't do this if you are unfamiliar with the registry and before you do do this export a copy of the Key in case you foul it up.
But if you copy the exported key then edit and import it will always work. Much better than trying to do it via lsp.
Mike Evans
Civil3D 2022 English
Windows 7 Professional 64-bit
Intel(R) Core(TM) i7-3820 CPU @ 3.60GHz (8 CPUs), ~4.0GHz With 32768MB RAM, AMD FirePro V4900, Dedicated Memory: 984 MB, Shared Memory: 814 MB