This is still an issue, that no one ever addressed. At this point double-clicking an .mcpack file will install multiple copies of the same addon. The "version" information in the json file is not being used for anything.
Likewise, Stonemason villagers will only accept SilkTouch stone, vs smelted stone.
Had to use PowerShell to delete, and then re-install, which installed the correct version: 1.16.30.56 RTX Beta,
Powershell (as Administrator) command:
Get-AppxPackage -allusers *minecraftUWP | remove-appxpackage