I feel everyone's pain in regards to the platinum for Modnation on Vita, as I have the PS3 version's platinum and I don't think I would ever want to go through that again. I got tired and ended up doing that myself with multiple PSN accounts.
Also, it looks like 14 of my platinum trophies are considered Ultra Rare, based on PSN Profiles. That makes 14 of my 103 Ultra Rare trophies platinum ones.