What's the problem with API V4 update to 4.3?
Here's a timely answer I just got from Eileen McNaughton.
"Contactlayouteditor 1.4.1 is compatabile with the latest apiv4 - so try upgrading that as well (it has been marked as needing CiviCRM 5.11 as that is the one that ships with the latest apiv4)"
So better to wait for 5.11 before upgrading this extension?