Properly installed... the kit recommended number of hinges wioll be FINE. Toothpick or other pinning is unnecessary too.

On the hinge material, draw a line using a crayon or china marker (grease pencil) where the hinge line will be. (both sides) Carefully insert the hinge so this line shows just a bit between the surfaces. (if you used black... the whole visible part should be black!) A pin can be stuck through the hinge material to aid in the alignment. (pull pins just before applying glue)

USE THIN CA. For a normal appx 1 inch sq hinge piece, 6 drops per side. Drip it on slowly enough to give time to soak in... rather than run and make a mess.

if you follow those tips.. 4 CA hinges are adequate for a .40 size Pylon racer's elevator (170 to 200 mph plane...) If it'll hold for that... the LT-40 is NOT going to be a problem.