Interesting. The websites say it seeds and will take over everything, though.
If the 4 o’clocks are the same ones my grandmother grew, they do re-seed, but they don’t take over. They like shade, so they won’t grow in the sun. She had them along the north side of her house, and they stayed confined to the bed — peacefully co-existing with with Vinca Major. They came back year, after year, without much attention. This was in the Central Valley of CA — about Zone 8, if I remember. This was in a narrow side yard in fairly deep shade.