If you can wait, you will eventually have more presents than you can spend on just your 'important' girls. I've long since passed the point where I have all the girls in my teams at 100% affection, and aside from frontloading affection on the occasional new gacha and event girls, I'm holding back on gifting so that I'll still have girls to whom to give gifts for daily missions.

Standard 'upcoming nation battle mode makes every girl important' disclaimer applies, and indeed makes the case for gifting 2* girls when you can.