What might be the unintended consequences? Would this be a per-rule item. If so, then it is good. If it would be global, then it might be that the condition not used in one rule would be essential in another. That would be bad.
I'm not sure. It was probably global variables, now called hub variables, that I was thinking of. In which case, it would not apply to this proposal.
"Rule Machine allows you to create local variables in each rule. These function similar to hub variables, except they are only available for use inside the specific rule where they are created. (Users of older Rule versions may recall global variables, which have effectively been replaced by hub variables and are also usable inside Rule Machine.)"