Well, for one thing, a reimplementation of a proposal could undo changes made by a later proposal. For example, suppose buckets of sand became inaccessible. Then proposal #62 would have to be reimplemented. As a result, the yellow paint rule would be reverted to the proposal #62 version. There would be no cause for proposal #68 to be reimplemented as well, so we'd end up with yellow paint all over the place again.
Other proposals just might not handle being reimplemented well. For example, suppose the M-train became inaccessible. Then proposal #98 would have to be reimplemented, and based on the wording of that proposal ("This proposal creates...two trains..."), I expect we would end up with two A-trains and two M-trains.
The other things I don't like are that it's not clear what "accessible" means, nor is it clear what constitutes a variable. As an example of the latter, in proposal #103, which of the following are variables?
- The frequency the robot moves
- The distance the robot moves
- The direction the robot moves
- The number of each type of card
- The name of the "Up card."
- The square identified in the "Up card."
- The overall effect of the "Up card."
- Which information is designated as public or private
Probably a lot of those would never actually come up, but I hope it illustrates my point.