isDirty works not as expected for file inputs

[RomkoG]

When I use <input type="file" /> it doesn't update form state isDirty prop as I would expect. I have some form with default values (which are actually presenting data record) and one of them is a file. Documentation says about isDirty:

File typed input will need to be managed at the app level due to the ability to cancel file selection and FileList object.
Do not support custom object, Class or File object.

However, it works fine if default value is a file and you set the input to be empty. What can I try to handle situations when it is required to know whether user has selected any file? At least how to make it track if anything was changed, doesn't matter if it is the same file as the default one, or not (I guess comparing files may be too complicated). Since it is mentioned in docs that File objects are not supported, why does it still handle that prop, so I can not set it manually, because it is reset all the time by the form... Is touchedFields object something that I should consider to use? Any other ideas or explanations?