Can I replace two smart objects at once in bulk and export using scripts or any other method.

Checkout the BatchMockupTemplates.jsx Script in my toolkit. Free Photoshop Photo Collage and Mockup Toolkit  The package may be more than you want and  you may need to modify your template to have the two smart object layer toe be replaced on top of the layers stack.  The could be duplicated of the existing ones the have their visibility off  and have been move to the top of layers stack.  They woul share the object you not have.  My script is quite simple it can populate any number of smart object layers on top  of the layers stack and populate any  number of mockup with replacement objects,   The replacement collections need to be in  folder in a collection of folders with the names  obj0, obj1, ... objn.  In your cast design in obj0  and color in obj1 if design is on top of the stack.   The script uses Replace content by default however replacement objects must have the exact sane size, aspect ratio, and print dip as the objects in the mockup templates.   If these are not exactly the same the smart object associated transform will nor work correctly.  These transforms  are not replaced or modified when replace content is used.  The Script can alternately  Edit replacements into the existing object.  Be fitted to fill the object  or be fit within the objects size and if need be rotated for best fit.