(I don't know the full history of exporting categories, but it seems to export ALL categories, having nothing to do with the account selected.  If so, it probably should not be necessary to select an account or date range.)
When exporting categories, only three columns are ever output.  Top level categories produce the category name and "I" or "E" (for Income or Expense.)    Categories below a top level category output the top level category name, the category name, and "I" or "E".  Lower level categories (although I have only tested one level deeper) only output the parent category name, the category name, and "I" or "E", but omit the top level category name.

The outcome of this is that the "I" or "E" indicator does not align for all categories.  It is in the second column for top level categories but in the third column for all others.  Categories more than one level deep in the hierarcy are output with only their parent category name, but their place in the hierarchy can only be implied from the preceding line in the csv output.

Perhaps the "I" or "E" can be in the first column, after which the full parentage of the category can use as many columns as necessary.

Perhaps a larger discussion of the purpose of exporting the categories is also in order.