In vCenter Client, attempting to change the vSAN witness for a vSAN cluster to a shared witness appliance fails with an error similar to, "Two-node cluster has 1300 witness components which exceeds max witness components limit 1000"
vSAN 8.x
Default component count for each cluster on shared witness is 1000.
This issue is resolved in ESXi 8.0 P06 (build number 24859861).
If upgrading is not feasible, please contact Broadcom technical support to implement a workaround.