Regarding bad battery life which was caused in my case by an underlying Android wlan diagnose process cnss_diag: You can kill it an observe that battery life is much improved and it has no negative side effects. As it is restarted as a service after reboot you need to comment all related lines within /init.qcom.rc to make it permanent.

Positive side effect beside improved battery life: browsing the internet is much faster now.

p.s. Within /data/misc/wifi there is a configuration file cnss_diag.conf which is used for dropping wlan logs to filesystem.