Currently FreeNAS GUI does not support setting rclone command line options. I needed to limit sync speed, therefore need to modify the –bwlimit parameter. I will show you how you can do that in current version FreeNAS 11.2-U7
Edit the following file
around line 106 and add bwlimit, example:
args = [ "/usr/local/bin/rclone", "--config", config.config_path, "-v", "--stats", "1s", "--bwlimit", "25M",
Then restart middlewared:
service middlewared restart
Start the job
Now start your cloud sync job and check that the rclone process is using bwlimit or any other parameter you specified:
ps aux|grep 'rclone'
Note: this will probably only work until you apply the next FreeNAS update.