There is enthusiasm and support for the overall goals of Plan S; however, there is also a great deal of concern about the implementation guidance and the very real possibility of negative unintended effects.
Hinchliffe, L. J. (2019). “Taking Stock of the Feedback on Plan S Implementation Guidance,” The Scholarly Kitchen. https://scholarlykitchen.sspnet.org/2019/02/11/with-thousand-of-pages-of-feedback-on-the-plans-s-implementation-guidance-what-themes-emerged-that-might-guide-next-steps/