How do I set ulimits for system-docker

Currently using RancherOS

[root@rancher-07 docker]# ros --version
version v1.5.5 from os image rancher/os:v1.5.5
[root@rancher-07 docker]# uname -a
Linux rancher-07 4.14.138-rancher #1 SMP Sat Aug 10 11:25:46 UTC 2019 x86_64 GNU/Linux

I need to understand how to set/modify ulimits for the system-dockerd process. Currently I am able to set/modify ulimits for the dockerd process by modifying the /etc/docker/system-docker.json file:

Example: Increased soft:hard max processes limit NPROC:

[root@rancher-07 docker]# pwd
[root@rancher-07 docker]# ls
key.json system-docker.json
[root@rancher-07 docker]# more system-docker.json
“default-ulimits”: {
“nproc”: {
“Name”: “NPROC”,
“Soft”: 512000,
“Hard”: 512000

After reboot I see the dockerd process has the changed NPROC but I was expecting this to also change the system-dockerd process ulimit as well.

What / Where do I need to make changes that effect the ulimit of the system-dockerd process?

Thanks in advance.