But if I try to force the List view, the checkboxes in front of the column names don’t make any difference. That is, after running the script, the columns are the same as before.
If Automator uses AppleScript under the hood (which I guess it does), then there’s indeed a bug in AppleScript that doesn’t apply the selected columns to the list view. In plain AppleScript there’s a workaround where you need to close the folder, then reopen it, in which case the columns will be applied as expected (if I recall correctly). Try to search the forum, there should be several discussions on this.
I tried the same Automator workflow as you presented in your initial post. In List View all I get is: Date Modified, Size and Kind. No matter how many of the boxes I check. I would assume this is a bug.