Can the general calling conventions in Russian (for example - Dimitri Ivanovich Petrov will be formally referred to as Dimitri Ivanovich) be extended to the countries of the former Soviet Union (particularly Ukraine and Armenia) ?
Russian-speaking Ukrainians and Armenians, when communicating in Russian, do expect patronymics used towards them in the same way Russians do, and mostly they do have a preference about rendition of their patronymic in Russian.
For instance, Armenian prime minister Nikol Pashinyan insists that his patronymic is rendered Воваевич in Russian, because his father's given name is rendered in Russian as Вова.
Etymologically, Вова is a hypocorism (pet form) of Russian name Владимир, that's why some Russian speakers call him Никол Владимирович, which he deems wrong.
Forming the patronymic following the usual Russian pattern for names in -а, -я (Фома > Фомич, Илья > Ильич etc.) would give Вович, but he does not prefer this form either.