When checking someone's private tefillin (or mezuzos) , is a magiha obligated to amend Tagei Kabollah that are not written correctly? (i.e. add if they are missing, scratch out if extra?) Most people I have asked over the years including those I learned from say not to. But I consistently see (mostly in) tefillin where these have been altered, most likely by others who have checked before me. It seems some are definitely those out there who feel strongly enough to do this. (Sometimes I even see the kaballah tagin have been played with but seemingly more necessary repairs overlooked.)
Id be interested to hear what others have to say about this?