Paul quotes Joel 2:32 in Rom 10:3, and the context implies Joel’s use of “Lord” actually designates Jesus as the one whose name we are to call upon for deliverance. (Read Joel 2:32,1 then read Rom 10:13.2) This seems to be a clear instance of Paul swapping “Lord” (i.e. YHWH) in Old Testament quotes with “Lord” Jesus (or rather identifying the two as the same Lord).
But so what? Plausibly...
• Romans 10:13 is not referring to Jesus.3
If Paul quotes Jeremiah 9:23-34 in 1 Cor 1:31, the context implies Jeremiah’s use of “Lord” actually designates Jesus as the one we are to “boast” in, for personally “knowing [the Lord]” in his greatness. (Read Jeremiah 9:23-341, then read 1 Cor 1:23-2:1.2)
But so what? Plausibly...
• 1 Cor 1:31 is not referring to Jesus.3