I heard an Avel should not add Kaddish. If I already Davened Mincha and said Kaddish after Aleinu since I am an Avel, do I say Kaddish again after Aleinu for Mincha at a second Minyan that I arrived at Ashrei?
Answer:
As an avel, the custom is to say the Kaddish after Aleinu, and this should be done even at a second minyan where you are not davening.
Although we don’t add extra Kaddishim, the Kaddish after Aleinu is not considered extra, but is rather a part of davening. If you are present at a minyan that completes Aleinu, you should therefore say Kaddish (as part of that minyan’s davening), and of course it is a zechus to do so.
Best wishes.