=paperless-ngx upgrade=
For upgrading bare metal I was successful with:
stop paperless services
cp -r /opt/paperless /opt/paperless.bak unpack new paperless-ng archive to /opt/paperless
do all python magic: sudo -Hu paperless pip3 install --upgrade pip sudo -Hu paperless pip3 install --upgrade -r requirements.txt
copy or adapt paperless.conf from .bak dir
migrate database: sudo -Hu paperless python3 manage.py migrate
start paperless services