In my organization often  enhancements of designs are approved while dev is working on previously approved version. 

Product managers are constantly asking for links of the prototype that will never change - a signed off link but Figma has no way of doing this unless I Have a copy of the file for each version and still I can’t guarantee someone accidentally won’t open the wrong file and change something inside. not to speak of the nightmare of confusion it can bring.

I work all updates that haven’t been signed off on branches and when I merge my branch link is dead. - Can we have a link from file history that can be shareable? I’m being asked to provide PDF which really can’t work on a dynamic variable based prototype unless I go through the manual process of capturing myself screenshots to put them in PDF which is painful to say the least.