@jan_soubusta theres already a Singer concept called
BATCH messages or
fast sync that allows you to skip most of the slow stdout piping by having the tap write directly to a file backend like S3 or even local files, then the target gets a small number of BATCH messages over stdout with pointers to those files. This allows the pipeline to take advantage of very efficient import/export features that many platforms provide, for example snowflakes
COPY command. This feature is relatively new to Meltano though so its not yet supported by a lot of connectors, hopefully soon!