The current design is that
we do not normally hash the files if there is an 'obvious' difference already (date/time, etc). There is an option to still hash them (all) anyway (for storage of the values for later use, but Free doesn't support any modes that can store the values anyway)
we do (optionally) hash the files if there is NO difference found in date/time, etc (in case differences exist where meta-data doesn't change, for example TrueCrypt containers)
What you're asking for is a reversal of the process (hash if metadata differences found anyway, in case the latter are spurious), which isn't there and is unlikely to be.
we do not normally hash the files if there is an 'obvious' difference already (date/time, etc). There is an option to still hash them (all) anyway (for storage of the values for later use, but Free doesn't support any modes that can store the values anyway)
we do (optionally) hash the files if there is NO difference found in date/time, etc (in case differences exist where meta-data doesn't change, for example TrueCrypt containers)
What you're asking for is a reversal of the process (hash if metadata differences found anyway, in case the latter are spurious), which isn't there and is unlikely to be.