I can’t speak for Fletch, but for me it shouldn’t even be a case of asking ‘when is the time?’. It shouldn’t be a given that there will ever even be a time.
Britain is a country, and chances to split it up should never be seen as a default, but as an extraordinary event.
I wouldn’t say ‘never’, but I think there should at least been a sustained period of several years, where opinion polling shows huge leads for a split. Like by at least 20% or possibly more.
Before we ever hold another referendum, it really should be obvious that Scots want independence, and will be settled with that outcome for good.