I don't really have a great understanding of Japanese internet culture, but as a Korean, I'm guessing it would be quite similar to ours in terms of "formality," as both Korean and Japanese have "formal" version of the language.
ex) する -> します / 하다 -> 합니다.
Suppose I want to ask for something, and I want it to go somewhere along the line of
"I know this might bother you, so it's okay if you decline."
"難しい頼みであることをわかっています. 困難であれば拒絶しても大丈夫です."
and I would continue on with whatever I need him to do.
(Now that I write this, I don't even know if this is even grammatically correct. lol.)
But the general question is: is it okay for me to presume that he will be bothered, and also give him an option to decline beforehand?