This is a tricky variant, not necessarily because a great deal hinges on it, but because the issues seem fairly evenly weighted.
Firstly, on the manuscript evidence, it does seem pretty clear that P46 lacked OLW. There is some damage, but there is no space for it. Here is the bottom of the relevant page:
And here is a bit more detail of the text as E[N T]W OI[KW:
The combination of P46, P13, B and the Coptic suggests this was an influential early reading (certainly in Egypt, evidence beyond that is limited). Since this reading is not the reading of Numbers 12.7 (quoted in Heb 3.5 and anticipated here in 3.2); and yet makes perfect sense here at 3.2 I think there is good reason to prefer the shorter, unharmonised, earliest attested text at this point. What do you think?