Hi Kimon,
I'm afraid that for SAP applications running on ASE we *do not* recommend to use the "dump tran with truncate only". Transaction log *should be* backuped out with a dump to disk or tape in order to ensure recoverability (Note 1585981 - SYB: Ensuring Recoverability for SAP ASE)
Those Notes might be also useful for Adarsh:
1801984 - SYB: Automated management of long running transactions
1588316 - SYB: Configure automatic database and log backups
Regards,
Victoria.