Yeah, these are good solutions too. Many times during design I've pondered whether to do solution 2, but I wouldn't because it is sort of complicated to pull off right… but now that we're seeing that mitigating the downsides of the simplest way (sequential evaluation) could be complicated too, maybe it's worth a shot after all.
I'll think about it. Don't hesitate to shoot ideas, I won't hesitate to steal them :).
edit: Evaluating mappings in the reverse order could maybe also work with minimal effort. For modulators, an evaluation in the correct order is better, but there will be cases where you want to add something in the middle of a series of transformations, and the problem will show up again.