The board is very compact and lightweight, and quite well supported at one end by the SLA chip itself. At the other end there is a PCB hole in the corner between the 2 connectors (as James said). Those 3 points total give plenty of support.
Re the 7078, I prefer the 7062, it still has 16th microsteps but the current is set by external resistors (not a little trimpot). The current does not need to be adjusted it should just be set at the proper value for the motor when the driver is built, and removing the trimpot from the design removed another cause of user error and failures from incorrect adjustment. It also eliminates a very common form of electrical failure as trimpots are one of the most likely failure components especially in a high vibration environment.
The SLAmStepper was designed to be small, very fast to build, and offer excellent performance and reliability. They are small enough to be built INTO the machine itself, or housed near the stepper motor even on small machines. My machine has the 3 SLAmSteppers in a little box behind the gantry.
