In Hieratic the tens and units, when referring to the days of the month, are invariably laid on their side… Traces of a similar use, though as regards the units only, are sometimes found in Middle Kingdom hieroglyphic...
We also observe, as Gardiner states, that unit number values (1-9) were written sideways/horizontally in later periods. However, on no occasion in the Old Hieratic palaeographic record do we find a cardinal number ∩ rotated 90 degrees from upright that is not a date.
This is what it comes down to. Is absence of evidence, evidence of absence?
The only way the number units could have been painted correctly onto the slab is as shown in my previously posted video - painted sideways, prior to installment.
So, could number values be laid on their side in the OK in other instances than for indicating dates (as in the MK)?