I'd definitely preferred to be called Vi in most circumstances, but Vivian is still a lovely name and it is still one I identify with. I don't intend to change my username in most spots online from Vivian to Vi, as Vivian is still a part of me, and she is the part of me I display online in many contexts. She just isn't the whole of me, hence why I'm going more by Vi

But Vivian is still fine

I am a bit of Vivian, I'm just also not entirely her, and I'd prefer to be called Vi by others for that reason. But Vivian is still part of me, and if you call me that I won't be offended. I still call myself Vivian pretty often