1.17.[0/1] Regression: Easy Motion now takes much longer and flickers twice while loading

Describe the bug
In 1.16.0, Easy Motion was fast and worked smoothly. Now it's slow and always has a double render pass for the jump markers that causes a long and noticeable flicker, contributing to the slowness. I've downgraded to 1.16.0 to solve the issue.

To Reproduce
Steps to reproduce the behavior:

1. Use native easy motion bindings or add the following to settings.json:

"vim.normalModeKeyBindings": [
    {
      "before": [
        "K",
      ],
      "after": [
        "<leader>",
        "<leader>",
        "s"
      ]
    },
    {
      "before": [
        "L",
      ],
      "after": [
        "<leader>",
        "<leader>",
        "2",
        "s"
      ]
    },
    {
      "before": [
        "J",
      ],
      "after": [
        "<leader>",
        "<leader>",
        "<leader>",
        "b",
        "d",
        "w"
      ]
    },
]

2. Press Shift+J while in Normal mode to switch into Easy Motion's word jump mode.

Expected behavior
Be fast. Only render the jump markers once.

Environment (please complete the following information):

• Extension (VsCodeVim) version: 1.17.1
• VSCode version: 1.50.1
• OS: Mac OSX Catalina 10.15.5

Start by reproducing Easy Motion with the native bindings or the provided settings.json on VSCodeVim 1.17.1, then compare its behavior with 1.16.0. Trace the Easy Motion loading and jump-marker rendering path; done means the operation is fast and the markers render only once without the noticeable flicker.