Oliver Cowdery supralinearly inserted “of the tree” with no change in the level of ink flow. Since either reading (with or without “of the tree”) seems quite possible here, we can surmise that Oliver’s correction was nearly immediate and not due to any desire to edit the text. Elsewhere in the allegory, we have one example of the singular branch postmodified by “of the tree”:
There is one more example of another branch in the allegory, but for this example (which is nearby in verse 24) there is no following “of the tree”:
Summary: Follow in Jacob 5:23 the corrected reading in 𝓟 (“another branch of the tree”).