Appreciate this is late, but this is still a problem in Mid 2021.
I am trying to recover 2TB of data from a Late 2012 iMac i7 with a 3.12TB Fusion drive where the HDD is failing (>10,000 Uncorrectable Errors). Amongst them precious photos and videos the user doesn't have a backup of.
The easy answer for me, coming mostly from the Windows world was to use DOpus, a powerful file manager for Windows that lets you carry out copy/move operations as "Unattended" operations with various options on what to do if any files already exist. It also has options to Ignore errors.
What's even better is you can just start the copy, set the options and walk away and it will even log each error, along with the reason, in a list that can be easily exported. You can download a fully functional 60-day evaluation copy at GPSoftware - DOpus.
DOpus has it's roots in the Amiga era and is still actively developed and supported today. My only affiliation is that I'm a long standing very satisfied loyal customer who uses DOpus in my role as an independent IT Tech to recover data from dying hard drives very often. I'd be totally lost without it.
I booted the Mac from a USB attached SSD I had High Sierra on, turned on SMB file sharing and set the options to share the afflicted user's home directory. Simply connected to the folder over the network from the Windows machine and initiated the copy. As I write this, 609GB of the 2TB has already been copied and I'm about to go to bed leaving the copy running.