Access cursor state (e.g. quantity) for use in contextual keymaps

[Acumane]

Looking to make contextual keymaps so that entering insert mode "starts" existing multi-cursors. I couldn't manage it myself with #STATE.cursors... here's approximately how I'd like it to work anyway:

...
local cursors = require("vscode-multi-cursor")

vim.keymap.set({ 'n' }, 'i', function()
  #cursors.STATE > 0 and cursors.start_left() or util.feedkeys('i')
end)
...

So in the absence of multi-cursors, i acts normally.