need a UDF or something to change drawings to dual dimensioning.

Perhaps you could make a mapkey to execute all the settings needed. Put it in either of your "used by all" config files, and let the users know what the key is. Possible drawback would be a conflict with particular users' personal mapkeys.

Yes, we have this. I created a mapkey that loads in a dtl file on top of the company dtl file to make these changes. I then made a button for it in the UI so all users need to do is click the button. Below is our mapkey:

!=================================================================
!== load Dual Dimension IN / mm
!=================================================================
mapkey loaddualinmmdtl @MAPKEY_LABELDual IN/mm;~ Command `ProCmdDrwSetup` ;\
mapkey(continued) ~ FocusOut `preferences` `InputOpt`;~ Activate `preferences` `Open`;\
mapkey(continued) ~ Trail `UI Desktop` `UI Desktop` `DLG_PREVIEW_POST` `file_open`;\
mapkey(continued) ~ Input `file_open` `Inputname` \
mapkey(continued) `Q:\\Folder\\Path\\dwg-setup_dual_dims_in_mm.dtl`;\
mapkey(continued) ~ Activate `file_open` `Inputname`;~ Activate `preferences` `ok`;\
mapkey(continued) ~ Activate `main_dlg_cur` `page_Annotate_control_btn` 1;

The dtl file looks like this:

decimal_marker PERIOD
default_tolerance_display_style STD_ASME
dim_tol_lead_trail_zeros SAME_AS_LEAD_TRAIL_ZEROS
dim_tol_trail_zero_max_places same_as_dim_tol
dim_trail_zero_max_places same_as_dim
dual_digits_diff -1
dual_dimensioning PRIMARY[SECONDARY]
dual_secondary_units MM
gtol_lead_trail_zeros SAME_AS_LEAD_TRAIL_ZEROS
gtol_secondary_value_precision ROUND
lead_trail_zeros std_english

We have one for mm/in as well

I couldn't get the UDF option in drawings.  Seems that it was only in the part file.  All configs are set except the switch to dual dimensioning.  Now looking at trying to set up a custom pick in the Ribbon.