MacBook Pro 13 Mid-2012
2,9 GHz i7 8GB RAM 500 GB SSD
After update to 19.9.2, com.apple.IconServicesAgent using 155% CPU… After looking here and at some other places without finding a straight solution (although, as you’ll see, in the end I followed a suggestion pointing to my user login items which, when I read it, didn’t convince me), I’ve found the problem and its solution, at least for me.
1) Went to console and, following other suggestion I’d found elsewhere, noted the PID of the process (264 in my case)
2) As per other suggestion, I typed the following at a terminal window:
ps awxu | grep 264
and the system answered pointing to «Default Folder X Helper»
3) I disabled «Default Folder X Helper» in my Login Items window and restarted. The problem persisted, but CPU usage went down to about 90-100%: Not enough!
4) Just reinstalled Default Folder X, checked "Enable at login" again at DFX's Preferences window, and restarted… And, so far, all is OK
Again, the key were steps 1 and 2. I hope this can help at least some of you, and I’d like to thank all those whose suggestions have helped me to solve this problem.