I responded to a similar wish earlier in regard to Vivaldi/Rossini DAC. I link to the thread.The situation in regard to Vivaldi Upsampler is much the same. I doubt that any such amendment is either technically or commercially feasible particularly having regard to the time that the range has now been in production. However it might be a consideration for the eventual replacement lines.
I will not comment on your subjective opinion on your experience of S/Pdif v. AES/EBU. For CD the data transmitted for either format is identical. It is unlikely that the superior CMRR of AES would have much practical advantage for circa 1m lengths. However it may not be the case that the S/Pdif and AES cables have identical sonic characteristics subjectively and you preferred one.perhaps it was this that you found?