HTML5 placeholder attribute used to hold default even after value change?

I have a HTML form that is used to modify preexising values. Thus on load values are prepopulated and upon submission, a check is made so that a confirmation message could be shown upon change.

We are currently not putting values in HTML placeholder attributes. Even if we do, we're not going to benefit from their general pragmatics, because the values will not be shown. However, for my UI logic, I would like to store initial/default values somewhere in the front-end and intuitively, the placeholder attribute sounds like a good opportunity to do so.

Could you think of any semantic arguments for or against using the placeholder attribute to store the initial values? I would mostly like hlp with a systematic overview of arguments, but individual strong arguments would also be highly appreciated.