cursor blinking before move to target line when use `Nj` or `Nk` when `N`, and seems like slow

Is this a BUG REPORT or FEATURE REQUEST? (choose one): BUG REPORT

What happened: cursor blinking before move to target line when use Nj or Nk, and seems like slow

What did you expect to happen: should target to N line down/up when Nj or Nk directly without blinking cursor

How to reproduce it (as minimally and precisely as possible):

• open new window in vscode
• copy page content from https://github.com/VSCodeVim/Vim
• goto edit mode, paste text inside vscode, file type should be text(try to make test simple without affected by other plugins)
• back to normal mode
• jumping by 10j, 20k, you will find the bigger N, blinking will take more time.

screenshot:

Environment:

vscode configuration relative to vscodevim:

/* Vim */
    "vim.enableNeovim": true,
    "vim.neovimPath": "/usr/local/bin/nvim",
    "vim.easymotion": true,
    "vim.incsearch": true,
    "vim.useSystemClipboard": false,
    "vim.useCtrlKeys": true,
    "vim.hlsearch": true,
    "vim.overrideCopy": false,
    "vim.foldfix": true,
    "editor.lineNumbers": "relative",
    "vim.insertModeKeyBindings": [
        {
            "before": [
                "j",
                "j"
            ],
            "after": [
                "<Esc>"
            ]
        }
    ],
    "vim.otherModesKeyBindingsNonRecursive": [
        {
            "before": [
                "u"
            ],
            "after": [],
            "commands": [
                {
                    "command": "undo",
                    "args": []
                }
            ]
        },
        {
            "before": [
                "<C-r>"
            ],
            "after": [],
            "commands": [
                {
                    "command": "redo",
                    "args": []
                }
            ]
        },
        {
            "before": [
                "<leader>",
                "e",
                "n"
            ],
            "commands": [
                {
                    "command": "editor.action.marker.next"
                }
            ]
        },
        {
            "before": [
                "<leader>",
                "e",
                "p"
            ],
            "commands": [
                {
                    "command": "editor.action.marker.prev"
                }
            ]
        },
        {
            // not working
            "before": [
                "<leader>",
                "e",
                "c"
            ],
            "commands": [
                {
                    "command": "closeMarkersNavigation"
                }
            ]
        }
    ],
    "vim.leader": "<space>",
    "vim.handleKeys": {
        "<C-a>": false,
        "<C-f>": true,
        "<C-n>": false
    },

• Extension (VsCodeVim) version: 0.11.2
• VSCode version: 1.21.1
• OS version: macOS 10.13.3

Start by reproducing the reported behavior in VSCodeVim with 10j and 20k on a plain text file, using the listed VS Code and extension versions if available. Trace the handling of counted j and k motions; done means the cursor reaches the target line without a delay or visible intermediate blinking.