Many people* but it has nothing to do with EU, the originator of Stellar Metamorphosis is Jeffrey Wolynski, he has written the most papers and there is a book now (still being worked on) > [vixra.org
] , *see page 39 list of people that thought about evolving stars and/or have supported stellar metamorphosis.
Papers Jeffrey > [vixra.org
My Papers Daniel > [vixra.org
EU does not have evolving stars, in EU stars/planets are formed instantly, the same as nebular theory. In stellar metamorphosis, stars and planets are individual objects with their own formation history.