What are the disadvantages for using short-field take-off technique?
Three main things:  


There is a little bit of increased brake wear because you apply them to stop, they usually creep a bit at full power, and when releasing them, there is also that short period where they are slipping while under pressure.  More wear than not using them at all anyway.  Of the three this is pretty trivial however.
Sitting stationary at full throttle has the engine at maximum heating rate and minimum cooling flow.  The area of the exhaust valve on the head heats up very quickly.  During maintenance, full power engine runs except for very short bursts are to be avoided without a special cooling box shroud, to catch large amounts of air and force it down between the cylinders, installed in place of the cowling.
The full power condition while sitting stationary turns the prop into a pretty powerful vacuum cleaner and it will suck up just about every pebble and bit of grit on the pavement (and even clean looking pavement is full of that sort of FOD).  Or water if you are over a puddle (and water erodes aluminum).  It will leave you wondering why you have to constantly have your propeller dressed out to clean up all the little stone nicks (this is why I always do run-ups over a patch of grass whenever possible).  Of the three, this is probably the biggest item in my experience.