I'm sorry, but could you explain your example a bit more? I don't think that I understand the issue here. If pm is redefined as a table through the let, why wouldn't we be able to access the macro version through the modifier? the table would clobber the variable version (@pm), but not the macro version right?
Local variables never override macros. In the first case above, the let will return the expected value correctly, because pm at that time hasn't been defined yet. In the second case, it will not return the expected value, because pm is defined as a macro, and (pm 1) gets replaced with whatever (pm 1) expands to, let notwithstanding.
