quick ?

hi, i am asked to bid on a roof coating job. It is a white granulated torchdown roof. i am not asking for prices! i would just like your input on whats the best kind of coating to use that i can roll on and provide the customer with more years in his roof life. Thanks in advance! I hear the acrylic elastomeric is the best but not sure.

Coating on that kind of roof is useless.