If someone has an obligation to say kaddish yatom (in this hypothetical, he is not davening for the amud and he is saying ma'ariv) should he speed up his own shmoneh esrei to be able to say kaddish or daven at his personal, slower speed which allows for better concentration, but miss the chance to say kaddish?
Is there a way to "weigh" the relative obligations or importance when choosing between the two? Does the ability to daven faster but the preference to slow down factor in?
If the answer is simply (as per the comments on the linked question) that saying kaddish at some point not tied to davening is what matters, a source for that would be useful. [I am not creating the hypothetical wrinkle that "he won't be able to get a minyan together at any other time.]