It looks like sometime in the last month the preview function has changed and now suppresses the customization tags, eg. [storenum,fallback=webstore] now just shows as webstore.
While I think this looks great, we were actually using the old functionality to allow custom previews internally; ie. a script downloaded the preview page and allowed internal people to try different customizations and we'd substitute the customizations ourselves.
Since this functionality seems to be gone, do you have a way to bring it back, eg. some query parameters I could pass in to do other substitutions or just to bring back the old behaviour? What about an API function to get such a preview, or the HTML of a current draft?
We did make this change as part of the ability to quickly add custom field tags in the editor itself. We don't have a way around that for you at the moment, unfortunately, it isn't something we'd really heard about people doing.
I'll pass it on to the developers to consider for the future though.
"custom field tags in the editor itself."
Did I miss the announcement this new feature?
Watch out in the next few days for a blog post about this, but you'll notice the change if you jump in and edit a template campaign.