Umang Raj

It is good to have the if block, but if you only have single extra output, then if block isn't necessary, that's why the sop_dualstar dosen't have it, but it will prevent confusions.
I think it isn't bad to use a member variable in this case, since you aren't using verbs.

the reason for this crash is the viewport, as you can see in the log, you can try cooking the nodes without viewport and it should work as a workaround, you should submit it as a bug report.
Also you can go to display options, under geometry tab, there are volume options, you should try setting the volume quality to very low and volume filtering (if your volume is fog) to off

can you send the crash report?