KiCad 6.0 is going to be released within couple of months. Now, I am using KiCad 5.99 on real projects. The nightly build versions have shown the new KiCad is as useful as commercial schematic/layout packages.
But due to the limitation of macOS, it is normally unable to launch two or more instances of an application. This is very very inconvenient since I usually have to copy/modify schematic between projects. So, I have to overcome this limitation so that KiCad can be a productive tool for me.
In fact, there is a solution by using AppleScript, though it is not perfect.
At first, we can create a new Application by using AppleScript. Then, we can change its icon with the original KiCad's icon so that we know the new application is used to launch KiCad.
Create an AppleScript
Open the Script Editor program on your Mac. After Script Editor launched, click on "New Document" button then enter the following line:
do shell script "open -n /Applications/KiCad/KiCad.app"
Then press Cmd + K to compile the script.
Press Cmd + S to save the file. Give it a name "LaunchKiCad" and set its location "/Applications" so that it will be saved as "/Applications/LaunchKiCad.app", and most importantly, select Application as the File Format.
Now I can double-click on the icon of LaunchKiCad.app, it will create a new instance of KiCad. Then I can repeat the action again to open another instance of KiCad.
Change the Icon
Once the script is in Application form, we can change its icon.
Icons on macOS are in the ICNS file format. We can copy the original KiCad.app > Contents > Resources > KiCad.icns and rename it as "applet.icns".
Two steps to do it:
Right-click the application and select Show Package Contents from the context menu. In the opened folder, go to Contents>Resources. We will find a file named “applet.icns”. Replace it with the one copied from KiCad.app.
Next, right-click the application and select Get Info. On the information window, the first section shows the application's icon. Drag and drop the the above applet.icns file on to the icon in this window. Now, the application will use this icon in Finder.