Failed to handle key `t`: command '0' not found

TO REPRODUCE

My Settings .json contains the following to mimic my vim keybindings....

    {
       "_comment":"Jump to Top",
        "before": ["<leader>","t","t"],
        "commands": [":", "0", "<CR>"]
    }

    {
       "_comment":"Jump to Bottom",
        "before": ["<leader>","b","b"],
        "commands": ["G", "$", "<CR>"]
    }

NOTES
• Normally I use <Space> as my leader key.
• Hence I use <Space>tt and <Space>bb to jump to top and bottom of files very quickly.
• <Space> + Same letter twice does not appear to work.
• Could this be a timing thing of the keystrokes?

...Regardless this is really irritating as navigating to top and bottom of files are some of the most common keystrokes I use.

Cheers,

Scott.

VSCodeVim version: 1.24.3

Error: command '0' not found
    at b.k (vscode-file://vscode-app/c:/Users/scott/AppData/Local/Programs/Microsoft VS Code/resources/app/out/vs/workbench/workbench.desktop.main.js:1669:3069)
    at b.executeCommand (vscode-file://vscode-app/c:/Users/scott/AppData/Local/Programs/Microsoft VS Code/resources/app/out/vs/workbench/workbench.desktop.main.js:1669:2985)

Start by reproducing the reported key sequences from the provided settings.json in VSCodeVim 1.24.3, using Space as the leader and checking the command '0' error. Compare the top and bottom navigation mappings and verify that repeated leader-key sequences execute without the reported error and reach the expected file locations.