Adjust table column width without changing the overall table width

When you say, "to update a column width," do you mean that you would like to adjust the column width to fit the contents of that column?

If so, have you seen my (not free): Table Tools for InDesign: AutoFit Columns - Id-Extras.com ?

No, there's nothing built-in, you have to do it yourself.

You're mixing two things: Shift+drag a column edge resizes just the two columns to the left and the right of the selected edge. Shift+drag the table's right border resizes all columns proportionally.

To keep a table's width constant after resizing a column, divide the change value by the column count - 1, then resize all columns except the changed column.

> I'm looking for a UXP solution

Does that mean you need more help to write a script that takes a value, resizes the selected column, and updates all other columns, or are you looking for someone to write the script for you?

While  moving the columns cell lines hold down the command/ctrl key.