[Avodah] What was actually written on the luchos, zachor or shamor?

[Marty Bluke]

We know that they were both said at the same time, but what was
actually written on the luchos themselves. It is clear from the gemara
that only 1 of them was written as the gemara comments that the mem
and the samech were b'nes, if both zachor and shamor were somehow
written b'nes the gemara certainly would have mentioned it.

R' Yaakov Kamenetsky addresses this question (in Parshas Vaetchanan)
and claims that zachor was written but the kri was shamor. He says
this would apply to all the other differences as well (kri uksiv).

However, this is very difficult as the end of the dibra of Shabbos is
completely different, in Yisro it talks about the 7 days of creation
and in Vaeschanan it talks about yetzias mitzrayim. On one word I can
see saying kri uksiv but not on a whole pasuk.

Has anyone seen any other mefarshim address this issue?