I know the issue is complex, and the designers had indeed put much attention trying to harmonize many criteria, including color assignments, proximity of related functions, frequency of use, menu access, and many other aspects. However, as happy and grateful as I am with the 34S, I would like to mention that the up and down arrows on the 34S are just one position off from the original 30B layout.
If the blue shift key in the original 30B were to be assigned to XEQ, the arrows may be kept in their original place, easing the current labeling issues. In fact, I think that the arrow keys, numeric entry keys and basic math symbols could be kept, perhaps with just new front-side stickers. As finger-induced wearing may affect the top-surface labels, I feel that an attempt to keep original printing where possible may be considered.
Just my AR$ 0.12