option to not update submodules when doing checkout

it seems to be a known issue that, at least when there are numerous binary files in a submodule, the submodule update process takes much longer than specifically checking out each submodule. I am, using libgit2sharp to do these checkouts, but the checkout on the superproject takes much longer (~5 sec for super vs <0.1sec for each submodule).
It looks like Commands.Checkout is, effectively, running:

git checkout [sha]
git submodule update --recursive -f

or something like it, but I just want the first line, not both. Is there some repositoryOption or CheckoutOption or something I can use to use it like this?

my usage of ligit2sharp is:

using (Repository repo =  new Repository(filePath))
{
   //logging and timing
   Commands.Checkout(
      repo,
      commit,
      new CheckoutOptions() { CheckoutModifiers = CheckoutModifiers.Force }
      );
   //logging and timing
}

從 issue 中所示的 Commands.Checkout、CheckoutOptions 和 CheckoutModifiers 型別開始，接著追蹤子模組更新在哪裡被觸發。驗證 checkout 行為，並找出如何透過一個選項抑制該更新；完成的標準是 checkout 可以跳過子模組更新，同時預設保留現有行為，並為新選項加入涵蓋測試。