--constraints affects every machine (controller and non-controller) in either the 'controller' or 'default' models. So what it does more than --bootstrap-constraints is:
a) Adds constraints for machines in the 'default' model
b) Adds constraints for non-controller machines in the 'controller' model
Actually, let me correct that.
--constraints affects every machine (controller and non-controller) in either the 'controller' or 'default' models. So what it does more than --bootstrap- constraints is:
a) Adds constraints for machines in the 'default' model
b) Adds constraints for non-controller machines in the 'controller' model