If you put a usb-c port in the 4 slots and put a charger in each one, it will damage the battery, or will it just charge faster?
It will charge normally and ignore 3/4 chargers
Unless of course you short something to force current into the machine in which case you deserve a destroyed laptop
In this case, that would be charging the battery that would draw a load
If OP screws around with the charging IC to allow all 4 ports charge the battery I’m sure it would result in damage in some form or fashion