http://rpgamer.com/features/2017/dotemu/dotemuint.html
MAC: We are excited for the Vita version that's still on the way, is it still on track for a May release? What challenges have you faced in bringing it to Vita?
CI: Yes, the release will be on May 30th as announced, and we are really excited! The delay is due to the fact that we made the mistake of working first on PS4. As it is a game from 2006, the optimization work in terms of performances was not too big. However, when we started to work on the Vita, we saw almost immediately that the performance optimization would take us a long time, as the device is made very different. We mis-calculated that. But the build we have in the office now looks and feels great and I cant wait to see people playing Ys Origin on the go.
MAC: What UI changes should we expect on Vita, as there were some tiny icons even on PS4? Will load times be comparable to those on PS4?
CI: We adapted completely the UI and tutorials in all languages, to provide the best portable experience possible. Also, as we had to do a lot of optimization work for the PS Vita, the load times should be the same or even quicker than on the PS4 version. By the way, the PS4 version will most likely be patched soon so players can enjoy the optimization work we did for the PS Vita.