It would be interesting to try to have actual registration so that the embossed design can interact with the printed copy rather that just being an arbitrary background decoration.
The way I understand your comment is you could have a scene or objects printed on a card, then line up an embossed design over the print to create depth or imprint specific areas of the print creating various effects. That would be interesting
also a tool that generates the emboss pattern based on the design of the card. so that for example a logo on the card gets embossed.
or the text in 3d, like credit cards used to be
I think that was not done by embossing but by "3d printing" on the business card directly.