I suppose I was the exception since I had flown control line for decades before reentering the R/C arena. I understood perfectly the effect of each hole of the control horn, why it is important to have the horn aligned over the hinge line, to be perpendicular to the surface and have all control surfaces at neutral with the servo and it's trim lever also at neutral.

When we brought our LT-40 to the field for our first buddy box session it was already bench trimmed. All the servos were centered with correct (low rate) throws being set via mechanical pushrod/servo/control horn geometry, the CG was exactly per specs, all decalage was correct as was ensuring the hingelines were exactly perpendicular to the fuse centerline.

The radio I used (and was used as the master radio) was a Futaba 6XA Super. It has limited but definite computer mixing - most of which I didn't understand. I *did* have about -15% expo cranked into the primary controls. The only trim change we had to make was to crank in some down elevator trim. I mistakenly went the wrong way, moving the elevator trim down. That was quickly corrected. In fact, my first flight was without the buddy box since our club's buddy box wouldn't work with my PCM receiver (I don't recommend PCM right away). I had to purchase a new R127DF receiver to continue training via buddy box. Once the LT-40 was at altitude, we simply handed the TX back and forth on that first flight.

I was surprised my CG wasn't checked. In my case it didn't need to but I'm sure the vast majority of beginners may NOT check theirs. We did fiddle with the low speed idle but were plagued with many deadsticks until I changed fuel and got some additional time on the engine. It had about a half gallon run through it before flying.

All I'm saying is don't require a student to invest in a non-computer radio. I didn't and am glad I didn't. I just flew it as a basic radio with the exception of model memory and expo. All endpoints were, and still are, at 100%. Most of the servo direction did have to be reversed but that would have been the case with a non-computer radio. My 6XA Super came with documentation on how to quickly set up a basic 4 channel airplane.