Please, explain lxd ipv4(6).routing and .routes network settings

LXD
1

Hi, accordingly https://lxd.readthedocs.io/en/latest/networks/
we can define preseed config like this

 config:
     core.https_address: 10.0.1.1:8443
     core.trust_password: xxxx
     #...
 networks:
   - name: lxdbr0
     managed: true
     config:
        ipv6.address: none
        ipv4.nat: true
        ipv4.address: 10.90.0.1/24
        ipv4.routes: ?
        ipv4.routing: true|false
   profiles:
      - name: default
      devices:
           eth0:
                 - name: eth0
                   type: nic
                   parent: lxdbr0
                   nictype: bridged

Please, explain, how it will be work with setting ipv4.routing: true|false and what purpose of ipv4.routes - is it will be equal to “ip route add some.additional.ip via lxc.container.ip dev eth0” or something another?