I would like to hear the worldwide sofrim's opinion on the following:
1)if the metayeg does not have ksav kabala would you sell it?
2)can you be sure all tagim on shaimos were done leshem kedushas hashem
3)now that there is kosher ink for rapidographs are you comfortable with metayeg using dyo min hashuk especially since many times he covers the original rosh.
4)when thick "beautiful tagim with ziyun are made is there shinui tzura after first tag(on nun)
5)very often the metayag widens the gag or "fixes" the original letter.
My conclusuion is on inexpensive mezuzos to have the sofer make the tagim even if they will not have ziyun better then falling into above problems.
In the case i must use a metayeg i have the sofer do bedek chaya (along with kav haschala no ziyun)and the metayeg shall do shatnez getz with dio lanetzach so we do not have shaimos prob