Hello zeroFX,
Yes, you can use Batch Manager to process several tasks for joining.
It is not supported to use Video Splitter commands, but you can fulfill this by following the steps below:
1) Save the join list then rename it from List.jxtl to List.xtl.
2) Then clear Join Manager and add another files for joining, save the second task to the List2.jxtl file. Add from this List2.jxtl file to the List.xtl file code from <group to </group> after the </group> and before the </timeline>.
3) Repeat step 2 for other joining tasks if necessary.
4) Replace strings <track video="-1" audio="-1" > with <track video="1" audio="1" >
You should get such code:
<timeline>
<group name="D:\Video\output\File12.mp4" out_type="mp4" mode="joining">
<track video="1" audio="1" >
<clip src="D:\Video\File1.mp4" start="0" stop="9584000000" timeFormat="100ns_units" />
<clip src="D:\Video\File2.mp4" start="0" stop="9584000000" timeFormat="100ns_units" />
</track>
</group>
<group name="D:\Video\output\Video12.mp4" out_type="mp4" mode="joining">
<track video="1" audio="1" >
<clip src="D:\Video\Video1.mp4" start="0" stop="9584000000" timeFormat="100ns_units" />
<clip src="D:\Video\Video2.mp4" start="0" stop="9584000000" timeFormat="100ns_units" />
</track>
</group>
</timeline>
5) Save the List.xtl file and open it in the Batch Manager. Start the batch processing.