Was there a Late Roman Clysma Just SW. of Ismailia?

The Maskhuta milestone (“From Ero to Clysma, 9 miles”) is often interpreted as evidence Heroopolis should be sought at Tell el-Retabeh. However, there is no evidence Retabeh was inhabited after c. 610 BC. While John Holladay, jr. does not mention any habitation at Maskhuta after the Early Roman period, Eduard Naville records that he found a Latin inscription reading “LOERO POLIS ERO CASTRA” in “a calcareous wall” here, page 21. LOERO may mean “locus of Ero”, that is, the place of Heroopolis. Thus, I suspect the true location of Heroopolis is at Tell el-Maskhuta itself, and that in the Early Byzantine era there were two Clysmas, one near Lake Timsah and the other near Suez.