Logs for the BigFix Client exist under that directory as seen below:
[pop@empoknor Logs]~ ls
20190907.bkg 20190909.log 20190912.bkg 20190914.log 20190917.bkg
20190907.log 20190910.bkg 20190912.log 20190915.bkg 20190917.log
20190908.bkg 20190910.log 20190913.bkg 20190915.log
20190908.log 20190911.bkg 20190913.log 20190916.bkg
20190909.bkg 20190911.log 20190914.bkg 20190916.log
I’d put the masthead in place that you want, restart the client and then look at the logs, they should be there. You may need to use sudo or be root to view the logs.