My channels-dvr.log was very big

sudo systemctl edit channels-dvr.service

[Service]
ExecStart=
ExecStart=/bin/sh -c '\
  TODAY=channels-dvr-$(date +%%F).log; \
  ln -sf "$TODAY" channels-dvr.log; \
  exec /PATH/TO/latest/channels-dvr >>"$TODAY" 2>&1'

Version updates through the admin GUI do not rotate the file, only service restarts or reboots.
The log file can still be followed via the web admin interface

They said they were trying to figure it out.

Log rotation is working on mine (docker container installs)