Disabling kinetic scrolling is already possible in current versions by setting the advanced configuration option "disable_fingerscroll". I have added this option as a checkbox to the preferences dialog in gPodder 0.17.0-6, so users will have an easier time finding it. Thanks for your feedback.

Version 0.17.0-6 with the more prominently paced "anti-kinetic"-option ;) is "it" now. 5 stars, no less. Outstanding application.