I have to admit that I am only in the Halflings chapter and do not have access to Sentient goods yet. However, there is currently access to the filters for goods that we have plus goods that we wish to offer. Are Sentient goods not added to the selections for those filters, once players reach the appropriate levels? This would seem to be a logical method to sort for such offers. If not yet developed, this would seem to be an easy addition for the developers.
On the flip side, I currently don't see such offers, or how they are placed/sorted in the unfiltered list. I could see the opposite problem where there are so many offers for Sentient goods that they pollute the list and make it unusable for searching general goods.
I am personally in favor of as much sorting/filtering capability as possible. Being able to slice and dice the data any which way is a good thing, IMHO.