I don't know, but I went to the following website that allows you to search on your specific machine model and then shows you all the parts that will fit it. I could not find a blind stitch foot, but did find the overlock foot #2N here, and they guarantee it will fit the machine. Here are all the parts I found for the 350PE:
https://www.sewingpartsonline.com/be...=desc&index=26
Edit: How wide are your decorative stitches? This website has a photo of the blindstitch foot and says it will fit Bernina machines of either 5.5mm or 9mm width.
https://www.bernina.com/en-US/Produc...dstitch-foot-5
Edit: I found this website that says the 350PE takes "new style" feet, in case that helps:
http://trashn2tees.blogspot.com/2017...o-bernina.html
Edit: Found the blindstitch foot here:
http://www.thecolorfulworldofsewing....r-Bernina.html
and it looks like Amazon has them too.
Final edit: I think you are okay as long as the foot has a red number. Not sure the ones made in Taiwan are original Bernina feet, though.
https://www.amazon.com/Bernina-Overl...dp/B075VVMK1F/