And the breaks notably may melt besides the landing gear suffering irreparable damage (to where you need to replace the landing gear). That's planned for and to be handled by the required fire fighting truck coming out and hosing them down if they start any signs of starting a fire, even though that will shatter the brake discs that were still good. The certified landing weight is about what weight they can be and still take off with no maintenance needed and just a regular refueling and perhaps crew change due to shift limits. But nothing done to the plane besides refueling. And yeah, it's because the extra capacity is just for extra fuel for extra range, so it's not worth the spendings on landing it more than just safely once.