Hey metnet

Look, i've never tried to access the file the way you do it. So i can't tell you why you don't see the "auto_frequent" option.
What i can tell you is, that "auto_frequent" is the first option you see when you open the miner.json file.

This is how the file looks like when you export it from the miner setting page (miner.json):

{"auto_frequent":"0","frequency":"900","check_nonce_submit":"1","auto_restart_miner":"1","restart_lower_limit_hashrate_5m":"4","restart_hw_count_30s":"74","auto_stop_miner":"1",
"stop_lower_fanspeed_in":"2000","stop_lower_fanspeed_out":"2000","stop_high_temperature":"70","temperature_unit":"c","refresh_time":"60","system_timezone":"Europe\/Zurich",
"system_hostname":"dayun","system_protocol":"static","system_ip":"192.168.1.222","system_netmask":"255.255.255.0","system_gateway":"192.168.1.1","system_dns_server":"192.168.1.1",
"pools":[{"id":130,"url":"stratum+tcp:\/\/lyra2rev2.eu.nicehash.com:3347","username":"xxxxxxxxxx","password":"x"},{"id":131,"url":"stratum+tcp:\/\/lyra2rev2.usa.nicehash.com:3347","username":"xxxxxxxxxx","password":"x"},
{"id":132,"url":"stratum+tcp:\/\/lyra2rev2.jp.nicehash.com:3347","username":"xxxxxxxxxx","password":"x"}],"user":{"id":15,"username":"xxxxx","password":"xxxxxxxxxx"}