Hello FluffyJoe16,
Thanks for reaching out to Microsoft Community.
We understand how important for you to charge the Surface device.
We would like to inform you that Surface Book 2 15" requires at least a total wattage of 102 watts to charge which means if you're going to use a charger lower than the requirements then it may charge your device slowly.
In addition, Surface power supplies are designed to work with Surface devices as well. With that being said, there is no harm if you will charge the device on a power supply rated at 127 watts as long as it's a genuine Microsoft or Microsoft-licensed power supply.
Hope this clarifies your concern.
Kind regards,
StevenK