I already asked a question about the alternation in germanic languages between the ing and ung forms of this suffix on the Linguistics Stack Exchange, but I didn't receive any satisfying answer and I thought that maybe this was the place to get better information on this topic.
I am aware that the ing form is used in Dutch, but I also know that an ig form is used in High Alemannic Dialects, frequently heard in Swiss German. Is this form with the i vowel used in any other High German dialect group other than High Alemannic?