It does matter.
Imperfective imperative is not necessarily rude if mitigated by some words of politeness and/or intonation and verbosity, i.e.
Ну, давайте, открывайте скоренько
Without such dampers it certainly may be perceived as confrontational, more aggressive.
I believe the difference between them stems from the fact that semantically perfective imperative is a one-off demand, which leaves to the addressee the freedom of refusal or non-compliance.
Imperfective imperative on the other hand expresses importunate persistent demand showing that the speaker isn't inclined to back off.
There's however a pointedly rude and disrespectful imperative which cannot be tempered by any politesse, namely past tense perfective form of a verb
This form not only demands action but demands that it invariably be done already.
Another ostensibly disrespectful form of imperative is infinitive form of a verb
Выходить по одному!
Ждать меня тут!
Still it can be acceptable in some formal hierarchical contexts such as army, penitentiary system and activities of law enforcement agencies, even in school, basically where degrading of human dignity isn't considered problematic.
And yet another unpleasant form of imperative is verb in present tense
Садишься за стол, пишешь объяснительную
Заходите, снимаете обувь
Смотрите видео, потом пересказываете
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