ctrl-v then G freeze editor.

[t9md]

Yes, this is known limitation and can't find solution by now.
visual-blockwise mode is achieved by Atom's multiple-selection feature.
Selection use marker under the hood.
When you do ctrl-v then G it try to add selection and same number of marker against ALL LINES OF BUFFER.
When you add many marker in Atom, it get very slow almost freeze, depending of your computer power.

So if you don't want editor freeze by your old finger memory, disable it to save your time.

# This work, any command not exist is OK to make keystroke useless.
'atom-text-editor.vim-mode-plus.visual-mode.blockwise':
  'G': 'DONT_MOVE_TO_LAST_LINE'

[t9md]

Sittin in README.md for a long time already. Nothing particular to do in this issue. So close.