You could maybe use this hook:
,----[ C-h v org-export-before-processing-hook RET ]
| org-export-before-processing-hook is a variable defined in ‘ox.el’.
|
| Documentation:
| Hook run at the beginning of the export process.
|
| This is run before include keywords and macros are expanded and
| Babel code blocks executed, on a copy of the original buffer
| being exported. Visibility and narrowing are preserved. Point
| is at the beginning of the buffer.
|
| Every function in this hook will be called with one argument: the
| back-end currently used, as a symbol.
`----
*if* it is invoked after the tag selection is done (I'm not sure if it
is or not). You would have to write some emacs lisp to remove the
:export: tags.