Assumption: This entire discussion applies to a SQL Anywhere remote database, NOT the consolidated database.

If the row on the remote database had a TIMESTAMP DEFAULT TIMESTAMP column that was not used for anything else (and presumably not included in the upload since that would violate the "not used for anything else" clause), then that column could be checked against the timestamp for the last successful upload for the publication that uploads this table. I think "the timestamp for the last successful upload" is to be found in SYSSYNC.last_upload_time column.

IF table.last_updated < SYSSYNC.last_upload_time THEN the-row-has-been-sent-to-the-server;

Can the row be updated on the remote after the earlier version is uploaded but before SYSSYNC.last_upload_time is set? ...the answer to that question may determine whether this suggestion will work, or can be made to work, or is just a load of hooey :)

-- SYS.ISYSSYNC (table_id 46) in SQL Anywhere 16 Demo - autostart and connect - Sep 24 2014 8:50:39AM - Print - Foxhound © 2014 RisingRoad
CREATE TABLE SYS.ISYSSYNC ( -- empty
   sync_id              /* PK        */ UNSIGNED INT NOT NULL,
   type                 /*         X */ CHAR ( 1 ) NOT NULL,
   publication_id       /*    FK U   */ UNSIGNED INT NULL,
   progress                             UNSIGNED BIGINT NULL,
   site_name            /*       U X */ CHAR ( 128 ) NULL,
   "option"                             LONG VARCHAR NULL,
   server_connect                       LONG VARCHAR NULL,
   server_conn_type                     LONG VARCHAR NULL,
   last_download_time                   TIMESTAMP NULL,
   last_upload_time                     TIMESTAMP NOT NULL DEFAULT 'jan-1-1900',
   created                              UNSIGNED BIGINT NULL,
   log_sent                             UNSIGNED BIGINT NULL,
   generation_number                    INTEGER NOT NULL DEFAULT 0,
   extended_state                       VARCHAR ( 1024 ) NOT NULL DEFAULT '',
   script_version                       CHAR ( 128 ) NULL,
   subscription_name    /*       U   */ CHAR ( 128 ) NULL,
   server_protocol                      UNSIGNED BIGINT NULL,
   CONSTRAINT PRIMARY KEY (
      sync_id )
 );
-- Parents of SYS.ISYSSYNC
-- SYS.ISYSPUBLICATION
-- Children
-- none --
ALTER TABLE SYS.ISYSSYNC ADD CONSTRAINT ISYSPUBLICATION FOREIGN KEY (
      publication_id )
   REFERENCES SYS.ISYSPUBLICATION (
      publication_id )
   ON UPDATE RESTRICT ON DELETE RESTRICT;
CREATE UNIQUE INDEX pub_site ON SYS.ISYSSYNC (
   publication_id,
   site_name );
CREATE UNIQUE INDEX subscription_name ON SYS.ISYSSYNC (
   subscription_name );
CREATE INDEX sync_site_name ON SYS.ISYSSYNC (
   site_name );
CREATE INDEX sync_type ON SYS.ISYSSYNC (
   type );