VMware added support for 4KN devices in 6.7; however, it appears to be local disks only. If you set the extent size to 4096 in TN/FN, it will error/timeout in ESXi 6.7. I wasn't able to trace any logs in /var/log/messages so you get left in the dark on what the issue is.
My suggestion is we evaluate adding a note under the "?" for logical block size on the extent that suggested 512 is recommended for ESXi.