I still can't see how you can use a macro to get them. The website itself is too damn slow to open them much faster than I could by clicking them. Mostly, I found that you just had to be on at the right time. Pink boxes would pop up, and then they'd disappear pretty fast. Either I'd get them or someone else would.
There was no shortage of pink keys. In the beginning of gambit, I could buy a bunch of gacha tickets and get pink keys. The Pero I got from unlocking boxes would usually make my Pero back, and I still get to keep the gacha tickets. That lasted for about two days. After that, I guess everyone figured that trick out because pink boxes were in short supply.
Gold and Silver boxes were always available but I could barely get a gold or silver key to save my life. Every time I'd fight a 2 or 3 focus girl, I'd get boxes. It's frustrating as hell to get box after box after box and never a key. I think I got something like 2 or 3 gold keys the entire event but I had dozens of gold boxes go to waste.