Run ahead feature for mame2003plus android shield tv

Hi, sorry to insist but is there some recent improvement of the run ahead feature for the mame core 2003 plus ? I use a shield tv android. i read that their is recents improvements on last revisions. I test some titles with this option but doesn’t seem to improve the latency. There is always 3 or 4 frames latency with the option ON and OFF. (I made tests with the frame key K and Pause to be sure) Hope a fully support will comes as the other cores. it would be marvelous. thanks