When you're putting your new siggy together, when you hit that submit button to check the sizing, your siggy instantly goes live. If someone happens upon a post of yours with that new siggy, or even a staff member, and they see that it's way too big, they could instantly report it or staff instantly removing the privilege of having a siggy without any warning.

It'd be nice if a new preview button was added so that you can preview your siggy and make any additional changes to it if it's too big before hitting the Update button. That way the improperly sized siggy wouldn't be instantly live when you're trying to make modifications to make sure that it's within the size limitations and the old one still live and active while the modifications of the new one are being made.

Yes to a preview - most forums/boards have a preview button when editing signatures

YES. Of all the things that need to be implemented, this is one that has been needed for years. ESPECIALLY since the sizing on here is known to be off by a few pixels at any given point. Text especially.

Caps for emphasis.

I have had multiple warnings for this exact thing. I support having a preview for our signatures and forum arts.

Yes please. Many issues surrounding forum images/signatures could be avoided with a working signature preview (and sizing tool, since it is almost always off).

This is definitely something I'd love to see implemented. I always spend too much time fussing with my signature to make sure I won't get in trouble, which is harder without previews.