If the exchange rate regime makes it difficult to make timely changes in the external value of a currency, then disequilibria can build up that add immeasurably to the abruptness and costs of the eventual adjustment. This is not just the recent experience of East Asian countries.
It was the experience of Mexico in 1994-5; and it was a substantial part of the explanation of the turmoil in the European Monetary System in 1992-3.