Sue --
More than a year ago, I came to these boards to ask about my husband's leukoplakia after an initial biopsy by an oral surgeon showed moderate dysplasia but warned of a possible "skip effect." Brian ended his reply to me with these words: "Keep an eye on this from now until forever."
A more thorough excisional biopsy a month later came back showing very-early-stage SCC. No further treatment was required, and my husband has been lucky that no other areas of concern have arisen (knock on wood!). He is checked every few months by an ENT at a top cancer center; in between those appointments, in an abundance of caution, he goes back to the local ENT who did the excisional biopsy.
I don't know if there are any in Australia, but in the US there are clinical trials of oral rinses and such to determine their effectiveness in dealing with dysplasia. Perhaps this is something you could discuss with your ENT, who sounds like he is on top of things.
All the best--
Leslie