I would file it down because if you want to become proficient with it you have to shoot it. For me to shoot it i would have to like the way the sights worked. I wouldn't accept sub par accuracy because of sights.
The three dot sights on the PK380 do shoot low if you use a traditional site picture. Line up the three dots and actually cover the target with the front site. Same as my Glock, Sig and M&P. Just concentrate on that front site and stroke the trigger. It will hit.