It's still 3% + 3%. Some gacha based games offer increased rate on special occasions, but for this game it might be months away if there's any at all.
If you get 2 5* in your first roll you're good to go. Unless you have favorite characters you are aiming for. 4* stars are already good enough for most situations and you can raise them to 5* once you have collected enough materials (20k feathers though....).

I would rather spend feathers on getting good units to 4*, then start saving for 20k. Arena battles can yield about 2k to 4k per week depending on how well you do in it.