From HCX 4.9 onwards, the size of HCX Manager upgrade bundle is larger than 5 GB which impacts the upload of pre-downloaded upgrade bundle initiated through UI.
For HCX Release prior to 4.8.2, HCX 9443 UI has a limitation of (5 GB) only to be uploaded through user interface.
HCX 4.8.2 release has support to upload upgrade bundle greater than 5 GB, hence its the only qualified release suitable for 4.9 upgrade if uploaded and triggered through HCX appliance-management UI (:9443).
IMPORTANT: If user has already downloaded the bundle using 443 UI in the HCX Manager system under "/tmp/upgrade/download" directory, then upgrade can be initiated through 9443 UI, as there won't be any need to browse and upload the bundle through UI. In that case, there won't be any restrictions required for any HCX release.