iTerm2 being slow after macOS High Sierra update

Thanks for filing an issue! Please answer the questions below so I can help you.

• iTerm2 version: 3.1.2
• OS version: macOS 10.13 17A365
• Attach ~/Library/Preferences/com.googlecode.iterm2.plist here (drag-drop from finder into this window)com.googlecode.iterm2.plist
• Attach a debug log, if possible. Instructions at debuglog.txt
• Are you reporting a performance issue or a hang? Performance issue. Sample_of_iTerm2.txt
• Are you reporting a crash? No.

Detailed steps to reproduce the problem:

1. Open iTerm2.
2. Press enter, scroll in any tab, open menus.

What happened: The entire iTerm2 app is laggy, and also makes the other apps/the system become slower. As soon as iTerm2 is closed, everything goes back to normal. Restarting and First Aid on the disk does not solve the problem. I don't think this is related to the 3.1.2 version, but some incompatibility with the OS.

What should have happened: Everything should be silk smooth like it was in macOS Sierra.