Robert-
I've never used it with graphics that require transfer tape over them for registration of cut vinyl elements. The people posting to the thread you linked to are addressing solvent printing on vinyl, FWIW. I assume they were having issues with the bond of their solvent ink to the vinyl being disturbed by the solvent in the coating. Whatever you use, I would imagine spray application, if we are talking liquid vs. film, will be required to not move the MK ink around if it is still smearing. Can you describe your application for this a little more? What are you doing with it, where, etc. Do the manufacturers say that these are aqueous ink compatible?
Also, thanks for the compliment on my site. Had to learn my way around a little web design to do it, as it is only the second site I've ever put together.