A note to anyone updating Sailfish through the OBS repository: please flash the kernel after updating packages through pkcon/zypper. Currently it is not done automatically (needs to be investigated, can be a problem with https://github.com/sailfish-on-fxtecpro1/droid-config-t5/tree/master/sparse/var/lib/flash-partition). It can be done with the following command: dd if=/boot/hybris-boot.img of=/dev/block/bootdevice/by-name/boot_a
The recent change was switching from userdebug to user build for Android adaptation bits (same as stock firmware), which uses different kernel config with lots of debug options disabled and greatly improves bootup time and overall performance. There is newly built CI image which has it already included, but otherwise updating packages and flashing kernel as described above should work for existing installations.
(Reposting from TMO for those who follow the topic here instead)