Hmmm not quite as interesting as I had hoped....I wonder what that note [3] references?
Not sure I follow his reasoning why he thought that Lucretius seems more motivated by the physics than the stated purpose of freeing from religious oppression, or why the practical minded Roman would not appreciate that. From a "practical" point of view very little would be more efficient toward happiness than overthrowing religious oppression. Maybe he's saying the Roman would be looking for information to use for better farming or the like, but if there is one thing the poem is devoid of it's "practical" application like mechanics or hydraulics.