WebStorm added the Attach project feature in 2019.2, giving me the multiple projects in one window. I just use the sdfcli in the terminal window to deploy a specific project in the same WebStorm project window and WebStorm hasn't crashed on me for awhile. I also suspect with the Attach project feature being so new the NetSuite WebStorm plugin will get an update to work without using the terminal window. I've also looked at VS Code with the SDF extension available in the marketplace, and while it works the entire dev toolset is richer in WebStorm.