While this may not be "officially" supported ... for those NOT running ESXi 8.0, you could uninstall Host Client 2.x VIB and install the previous release. When the next patch/update, all system packages will be overridden with the version included in the patch/update
I just ran a simple experiment with ESXi 7.0 Update 3i, which includes Host Client 2.x.
Step 1 - Downloaded ESXi 7.0 Update 3g (there's no H) offline depot (zip) and extracted the contents and find esxi-ui folder which should contain VMware_bootbank_esx-ui_1.43.8-19798623.vib
Step 2 - Uninstall the Host Client 2.x VIB using ESXCLI:
[root@localhost:~] esxcli software vib remove -n esx-ui
Removal Result
Message: Operation finished successfully.
Reboot Required: false
VIBs Installed:
VIBs Removed: VMware_bootbank_esx-ui_2.1.1-20188605
VIBs Skipped:
Step 3 - SCP previous ESXi Host Client VIB to desired ESXi host
Step 4 - Install the previoius ESXi Host Client VIB using ESXCLI:
[root@localhost:~] esxcli software vib install -v /VMware_bootbank_esx-ui_1.43.8-19798623.vib
Installation Result
Message: Operation finished successfully.
Reboot Required: false
VIBs Installed: VMware_bootbank_esx-ui_1.43.8-19798623
VIBs Removed:
VIBs Skipped:
Reboot the ESXi host to ensure everything persisted (which it did) and login to ESXi Host Client and verify that adding VMDK to existing VM workflow is successful (which it is as it is using the prior version).
I personally don't see harm in this workaround since ESXi Host Client is simply a "client" to underlying ESXi API and for those that only have standalone ESXi host and don't have vCenter Server or simply using the Free ESXi license, this at least gives you viable UI until a new update is available with the fixed ESXi Host Client