They fly great with a 25LA as well.
With a 25 they are plenty strong without any extra bracing. If I build another one the only strengthening I will do is to include a small stick on the top of the wingtop former sheet. Id you catch a wingtip that spot is kinda light.
I've had both the LT-25 and the LT-40 (actually still do). I like the 25 better. It's a little more responsive but you can slow it down and it will be a lot easier for beginners than the great majority of the popular trainers.

Larry