Fileformat for images from "Extras" tab

[maniac-0s]

In setting I can use a pattern like [seed] [number] etc to set the filename of the generated image when saving. But this doesn't work for the "Extras" tab. Since I very often upscale my images, it is really annoying that it has a running number 00001.png or something and I constantly have to change the name before saving because I already had a certain number before. I wanted to include at least the seed in the filename but I can not find any settings to do so.