Looking for a new "Sandisk X110 SD6SP1M-128G 1002" SSD"

It seems the SSD you are asking about is an OEM only SSD. When manufactures sell SSD to a host manufacturer such as ASUS many times there are firmware modifications specific to the host manufacturers platform. Additionally it is not likely sandisk retail support would have all the information regarding OEM devices since these devices are not supported by the retail support team. Your best bet will be to contact ASUS directly and see what they recommend.