I also support this idea.
Even though digital files are more or less easily converted
to any desired scale (*), it would be a nice touch to know
the scale of the model before downloading it.
Some designers/uploaders take care of this and provide
the information on the title. But there are many that don't.
A specific entry about scale on the download description
of the kit would be good. Not that I consider it essential
or specially relevant. But since some modelers prefer
certain scales, it can be helpful if it can be implemented.
* paper size restrictions apply.