Ok, so I’ve solved the problem:
I’ve booted into Windows and installed the MSI Creator Center (the dedicated Windows App for this model). I’ve set the option to stop charging at 60% and start charging at 50% then rebooted into Linux.
The battery is currently not charging even though it is lower than 100%.
Lacking other Linux only method of limiting charge level, I’ll mark this as a solution.
Should anyone find a method that doesn’t involve Windows I’ll be glad to mark that as a solution.