Ya just saw that. I think He's right! So were can you buy an SX300 Chip I google searched and there are no places I found 
not according to Nodus on the discussions:
"it looks to me that they aren't gonna be good for the SX350 as they put the window too low to accommodate the length of the chip and the usb charge board. They made a huge button hole which when used with the switch included will interfere with a fat daddy or varitube 510. If they had left the buttonhole and window out I would snap up a couple of these but alas not to be I guess. "