Also, any constructive explanation on the process of creating tags would be appreciated.
Asking on meta is a good first step before creating a tag. We generally discuss tag creations here first. However, providing a list of applicable challenges and posting some suggestions for the scope of the tag are really helpful for starting a constructive discussion.
As for your specific suggestion, in general it seems like a good idea. The scope is a more important question here. It's probably not worth tagging every challenge which allows input or output in scientific notation. Instead, we should probably use the tag for challenges which are specifically about manipulating scientific notation. But even then we should be careful to make a distinction between the new tag and the existing floating-point.
So I'd suggest you add those challenges you have in mind into your question so we have something more concrete to discuss. I'll edit my answer accordingly then.