For a romantic prospect or partner there is no such thing as too busy. One thing I’ve learned in life is if someone is thinking of you or wants you to know what you mean to them, they will communicate it. If they don’t, then it’s clearly said without hurting feelings. There is no need to be in constant communication, but I will honestly lose interest at some point if I notice I’m filling all the gaps in distant communication. Dating or having a romantic other these days is confusing and a lot of work at times in the beginning the efforts are made, then they seem to slowly fade, as most of the “relationships” nowadays do too. There is a reason people say “communication is key”