High Sierra issue with mouse in other apps

Whenever MacVim is open I am having weird cursor jitters/slow-downs in other apps. Like any app using the equivalent of an NSTextField. When I hover the text field with MacVim open the cursor speed slows down by at least half and becomes jittery.

I've noticed this issue in Firefox Nightly and Xcode and it goes away as soon as I close MacVim. In Xcode, it even happens when I'm editing a storyboard and add an NSTextField.

I haven't been able to figure out when exactly it is triggered but it does not happen just from launching MacVim. It seems to be some combination of full screen and changing window focus.

この issue ではファイルもテストも指定されていません。まず、MacVim を開いた状態で Firefox Nightly または Xcode におけるカーソルの低速化を再現し、フルスクリーンモードとウィンドウフォーカスを変えて確認してください。影響を受けるテキストフィールドで、ちらつきとカーソル速度の低下が発生しなくなれば完了です。