The three adjectives omnis, cunctus, and universus appear to be essentially synonymous. They are often used in the plural. The entries in L&S suggest very strong similarity, but I find it unlikely that they would be exactly identical in all uses. (They are metrically different, but such poetic considerations do not interest me here.)
Are there any differences between these words? Is there a situation where choosing between these adjectives can lead to three different meanings? I am mainly interested in classical Latin, but insights about later use are of course welcome.