Stepping away from the bannneton

Hi folks, I’ve been doing sourdough for some years but all my stuff is proved in bannetons. 

I find when I tip out of a banneton there is a tendency for the dough to sag.

The other day I had to leave my douch for a very long time and came back to an over-proved dough. Rather than throw it out I shaped it up again. One loaf I plaited, the other I made a small batard. They had no additional prove but went straight in the oven. 

This made me think. I’m interested in learning how to adjust my mix so I can do things I used to do with regular yeasted doughs, but now with sourdough - plaits, cottage loaves, rolls.  “Self supporting” objects during that second prove. 

Any pointers on where to start?