Ruling on cutting off the last two units of prayer in a congregation one joined in the final tashahhud in order to catch another congregation?

The questioner:
Peace be upon you. May Allah keep you in good health, O Shaykh. I have three questions, O Shaykh. I have three questions. O Shaykh, if I join a congregation in the final tashahhud, and before the imam says the taslim I hear that another congregation has begun, O Shaykh, is it permissible for me to turn the obligatory prayer into a voluntary one, say the taslim, and join them?

The Shaykh:
I cut it off and go to perform it; that is not the only option. There is no harm in it. If you cut it off, it is not befitting for you, because you are moving to what is better.

The questioner:
I mean, what if I turned the voluntary prayer, O Shaykh?

The Shaykh:
If you make it a voluntary prayer of two units and go to them, that is fine, everything is fine.

The presenter:
Yes, this call was made to the honorable Shaykh 'Ali Zambaz on Friday evening, the second day of the month of Rajab, in the year 1416 AH.