batch export multiple 1200 dpi bitmaps

  • I make my comics in 600 dpi, but my publisher wants text files in 1200 dpi bitmap files.
    Normally I put all my hand drawn text on a vector layer, then change image resolution to 1200 and export the pages.
    Because it's a vector layer, the quality also gets enhanced to 1200dpi, creating crisp text.
    But even with an action this is a lot of work.
    I could do a batch export of multiple pages, (like I do for the color pages)
    and then just change the dpi to 1200 and color to duotone threshold in the export box.
    However, when doing this, the quality of the text on the vector layer looks like it's 600 dpi, blown up to 1200.
    Is there a way to prevent this?
    ie, force clip studio to scale the vector layer properly before exporting?