Its possible to crosflash IHAS124Y to 224,324 or 424?
Sure, it's possible, but since the 'Y" series is based on the NEC chipset, you won't likely find any information on this site to allow it. You won't gain the LS capabilities from the 224 and 424 drives due to missing hardware.
You could "crossflash" from 124 to 324 or from 224 to 424 by just changing 4 Bytes in the firmware. But you won't gain any benefit from doing so as these firmwares are mostly identical - except for maybe a couple of Bytes.