A non smooth big bang should be a symmetric string based black hole nucleus explosion, into ever more exponentially smaller BHs and a tetrahedron based vacuum with variable Planck length edges.
see: https://www.flickr.com/photos/93308747@N05/34445454512/in/album-72157639797727585/
https://www.flickr.com/photos/93308747@N05/albums/72157639797727585
see also: http://motls.blogspot.nl/2017/06/turoks-bogus-criticism-of-hartle.html