I was thinking that maybe SSU could be turned off just for the filter...not to touch it, leaving SSU to work elsewhere. I guess not.

Looks like you'll have to choose between SSU and the filter.

But eventually you'll have to upgrade to the new 1.5 cart anyway, and it looks like SSU won't be going with you (us).

If CEON's URI can rewrite the urls exactly as they are now on SSU, perhaps you can "take your urls with you" to that CEON mod and the new 1.5 cart. I've read about this theory before. Keep the url and move from platform to platform, taking the url with you. That assumes the new platform can re-write the same way.

Would it be possible to take a look at your site, just to see?

sph
www.prommart.com