DVD Architect does not re encode if it is given fully compliant files . Files from Vegas or EDIUS will work fine. It will of course need to encode any menus created and format for BLuray iso. I like it because one gets to author once and then feed the appropriate file for DVD or Bluray. Creation of iso on my Threadripper takes about 30 mins for a 2 hour Bluray so it certainly is not re encoding. Equivalent for the DVD is seconds. I do not let DVDA burn use Nero most of the time.
I have not tried, but DVDFAB has a UHD authoring application. https://www.dvdfab.cn/uhd-creator.htm?trackid=headmenu2,headmenu2
I have not tried, but DVDFAB has a UHD authoring application. https://www.dvdfab.cn/uhd-creator.htm?trackid=headmenu2,headmenu2