Few would argue that the United Kingdom’s or Italy’s departure from the ERM precipitated an economic crisis or led to any lasting hardship. I would make the same case for Australia in 1985. The depreciation of the exchange rate in these cases led to a beneficial policy response, had only short-term inflationary impact, and was soon followed by a significant appreciation.
It seems to me that a fruitful approach would be to look at the factors which are likely to precipitate a currency crisis, and look elsewhere for another set of factors which would cause a currency crisis to lead to a full-blown economic crisis. By this, I mean a deep recession, high inflation and widespread corporate and banking collapses.