The only work around I have found is to specify a standard variant in SQ01 that has a default value of '*' in a field that will bring back all the records.
For example, in a query with an infoset using table TGSBT, even thought the table only has 228 values, the box asking for number of datasets to be read with a default maximum of 100 appears.
When '*' is used in the selection field using TGSBT-GSBER, the box doesn't appear.