On Mon/Thu mornings between the קדיש associated with תחנון and taking out the תורה, why do Ashkenazi Siddurim typically print two versions of אֵ-ל אֶרֶךְ אַפַּיִם? One is usually called "מנהג אשכנז" and the other "מנהג פולין".
According to Machzor Vitri the Shliach Tzibbur says ......אל ארך אפים ורב חסד ואמת and the congregation responds with ......אל ארך אפים מלא רחמים. This is done immediately prior to opening the Ark for the reading of the Torah. This would indicate that the placement did not change. However the question remains why do we say only one or the other.