Found this PC tool for editing common.bmssv and noticed the creator didn't post it here
This tool was created by KhaosVoid who has not been active on this site for a few years
Basic Tut
1) Get your game save from your switch using JKSV or your choice of save tool
2) Copy your save to pc either using FTP or manually (recommended to make a backup)
3) Run MetroidDreadSaveEditor.exe and select Open File
4) Edit your save to your liking and select Save FIle
5) Now just copy the save back to your switch and enjoy
https://github.com/KhaosVoid/MDSaveEditor
This tool was created by KhaosVoid who has not been active on this site for a few years
Basic Tut
1) Get your game save from your switch using JKSV or your choice of save tool
2) Copy your save to pc either using FTP or manually (recommended to make a backup)
3) Run MetroidDreadSaveEditor.exe and select Open File
4) Edit your save to your liking and select Save FIle
5) Now just copy the save back to your switch and enjoy
https://github.com/KhaosVoid/MDSaveEditor