Purpose of salt?

Toast

Other than flavor, is there a purpose for salt in a recipe that only calls for flour, yeast, water and salt?

To control leavening, and to tighten dough structure. 

Without salt, fermentation can proceed too quickly to develop enable flavor development. 

Salt also tightens the dough; without it it might become too flabby/extensible. 

I am not on a salt restriction, but I hear it oxidizes and 'can be' harmful to yeast. I was just wondering.

Normally I put the salt in at the very last minute before kneading.

If you put the salt in last minute, how does it dissolve and get distributed??  

I would think salt has to be added to some liquid (like water) for distribution.

I add my Salt after I mixed the flour and Water and a 50 minute Autolise.

I just add the Salt over the top of the dough and work it in by folding the Dough over itself a few times and if you knead than you will distribute the Salt just fine.

You could keep some of the Water and disovle the salt in to it and add it that way after the Autolise.