I actually think that if Buggy got stronger he too could also gain a "Gear Second", granted he probably wouldnt call it that.
I think that Buggy could totally split up his body into pieces so tiny, he could become like sand. His body splitting into parts as small as grains of sand, and being able to avoid attacks like a logia. It would be like a SUPERRR version of his Bara Bara no Festival, dont you think?