Hello
If you still do not have the solution for your problem here are my ideas how to solve this:
1. Implement onsort method for the view controller which you want to sort the data one.
2. In the DO_PREPARE_OUTPUT method put code to sort the result list:
IF iv_first_time = abap_true.
me->typed_context->srvreq->collection_wrapper->sort(
iv_attr_name = NAME_OF_COLUMN
iv_sort_order = SORT_ORDER_U_OR_D
iv_stable = abap_false ).
ENDIF.
regards