Import-AFXml (PowerShell) should have ContinueOnError option
Both AFImport.exe and ImportXml (AFSDK) have options to continue on error (like is something is checked out or if there is a duplicate element name). For some reason the PowerShell version doesn't. This should be added.
James Lewis commented
There is a common powershell parameter called ErrorAction. Unfortunately setting this to SilentlyContinue, Continue or Ignore results in the import stopping and a check-in of some new objects and other objects are left in a checked out state. If ErrorAction is not defined, the import stops and does an undo check-in. Perhaps this common parameter could be implemented properly to solve this request.
As a workaround, I'm using the powershell cmdlet start-process to start the afimport.exe.