Forget this topic, the notion that "everything is banned unless mentioned in the rules" is definitely not correct and the rules certainly aren't written that way in any other case. At least in the US, the law works (or is supposed to work) the same way - you can to anything you want as long as there is no law against it.
Yes. However I do not know AMA rules and I am not lawyer, but our rules have also parts telling that C/L model has fixed wing and it is controlled by lines and does not say that R/C helicopter is banned, and anyway, you cannot come and compete with R/C helicoper in F2B :- ))) ... So yes we have parts telling that allowed is only "something" and nothing else. Simply we have definition of event and tdefinition exclude alll beside allowed, without specificaly banning all other. That definition of c/l is especially about system of control, so I think any autopilots ARE banned also without specific wording, unfortunately it could be only my interpretation.
I think if rules say model is controlled by pilot, then my understanding is that it cannot be controlled by clockwork. The problem is, (as we saw in past and as we see also in this thread) that someone consider the clock work for whole pattern rule breaking, but not single figure executed by lines (because it WAS controlled by pilot - he started it), or someone yes but not the single turn (corner) ... or corner done by pilot, but improved to exactly 90 degrees by some other trick, or simply some active stabilization unit. Who can say what is still ok and what is not? Whwre is the border? That was reason why I always commented that all such devices should be banned. Simple bacause:
1/ we cannot clearly say what is allowed and what is already rule breaking
2/ we cannot INSPECT all tricky devices especialy if implemented as program running in black box if they are breaking rules or not IF we would be able to say where is border.
But that all is not only about bellcrank and elevator. None can today imagine what everything could be done as we did not try yet. I have on desk several working tricks which I developed and they improve flying, but I told myself I will not be the first using such things. May be someone remembers my pictures with servos and PCBs sticked on model. There are many thing from stabilization, automatic trimming, compensation of tubulence, side wind, tip weight adjusting ...... if we do not want model full of electronic, we will need ban all of that sooner or later, and the only clean way is to allow only direct (means without any timing functions and power steering) mechanic controll system. It is inspectable and does not allow clockworks.
Yes I heard I am trying to stop spinning of world, but simply I think that is the only way.