P. Vaychi, P. Vayeishev - When did Yosef become the B'chor? 1 - Sources, Q's

Sources:
Vaychi 48:5

Vaychi 48:22
Torah T'mimah there 17
Quoting TB Bava Batra 123a

Vayeishev 37:3
"K'tonet Passim"

Questions:
When did Yaakov choose Yosef to be the Bechor?

Is it Vaychi 48:5 when Yaakov said "KiR'uven v'Shimon yihyeh lee"

Vaychi 48:22 "shchem echad al achecha"?

Note: Both implying pee sh'nayim...

OR

Vayeishev - when Yaakov gave Yosef the K'tonet Passim; which implied that Yosef now held the mantle of "B'chor"?

BE"H we will cover Vaychi next and reflect back to Vayeishev and Vayishlach later.

Note: Stay tuned for "surprise twist ending"
Hypothesis. :-)

Shalom
RRW