We go back to the Real issue: Is the Sinaiticus authentic?
It doesn't matter if Tischendorf was a thief and/or if he lied about how he acquired the Codex.
The Real question is the age of the Codex.
I agree, that is why I smile a lot at the contras trying to make the issue Simonides Perfectionalism.
The integrity of both Tischendorf and Simonides are reasonable discussions, with some significance, but the main issue does boil down to the history and condition and text and anomalies and provenance and phenomenally good condition and colouring and linguistics and palaeography of the manuscript.
And how deeply entrenched scholarship (think evolution as an example) works, or does not work, making for circular analysis as the norm.
Outside of that, the most important issue is the impossible knowledge of Simonides and Kallinikos and the absurdity of their claim if they did not have the inside track, e.g. if there was simply any provenance the issue would have been over in a matter of days.
"Look, here is the ancient catalogue, here is what the church figure wrote about it when it arrived, when it was put in the library, etc."
Simonides was not concerned with that one whit, because he knew 100% there was no manuscript before 1840. Nobody writes accurately about future manuscripts.