Increase maximum allowed images in a signature?

At least to five. Four is a bit low, in my opinion.
The images themselves are rather small, as you can see.
Same size as the other ones. Would make my signature more defined, in my opinion.

I don't see it as too low. I don't want signatures to take up half a page.

Thomas wrote:

I don't see it as too low. I don't want signatures to take up half a page.

Signature size constraints would fix that issue.
I'm talking about smaller images, similar in size to the ones currently in my signature.

Fair enough, I've up'd it to 10.