Package upstream udev rules
The upstream provides a very useful baseline set of udev rules: https://source.puri.sm/Librem5/feedbackd/-/blob/main/debian/feedbackd.udev
Without such rules, feedbackd doesn't really do anything useful, at least on the device I tested with (Samsung A5). Vibration/LED devices need to be tagged with uaccess and given a FEEDBACKD_TYPE.
Alpine is already packaging these rules wholesale: https://git.alpinelinux.org/aports/tree/community/feedbackd/APKBUILD#n41