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...
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...