There's currently no way to have two instances of Spine use different preferences.
If you want to use one set of preferences with one Spine version and another set of preferences with another (and don't run the two versions simultaniously), you could:
- Set up the preferences for the first version, copy prefs.json to e.g. prefs.4.1.json in the same folder
- Set up the preferences for the second version, copy prefs.json to e.g. prefs.4.2.json in the same folder
- Write a batch file for each version that will copy the prefs.x.y.json over to prefs.json, then starts Spine.
Assuming you are working on Windows, and you created a prefs-4.2.39.json and a prefs-4.1.23.json file. here are two batch files that you can run:
For 4.2.29
@echo off
REM Batch file to start Spine 4.2.39 with correct preferences
REM Copy the correct preferences file
copy /Y "%USERPROFILE%\Spine\prefs-4.2.39.json" "%USERPROFILE%\Spine\prefs.json"
REM Change to Spine installation directory
cd "C:\Program Files\Spine"
REM Start Spine with specific version
Spine -u 4.2.39
pause
For 4.1.23
@echo off
REM Batch file to start Spine 4.1.24 with correct preferences
REM Copy the correct preferences file
copy /Y "%USERPROFILE%\Spine\prefs-4.1.24.json" "%USERPROFILE%\Spine\prefs.json"
REM Change to Spine installation directory
cd "C:\Program Files\Spine"
REM Start Spine with specific version
Spine -u 4.1.24
pause
You can put those files anywhere, e.g. on your desktop, and double click them to start the specific Spine version with the respective preferences.
Note: if you change the preferences in Spine, you will have to the prefs.json file over to prefs-x.y.z.json to update it!