[cle]

My interpretation was that flat $ amounts are leaving a lot on the table, with the extreme divergence of COL in cities vs. suburban vs. rural areas.

And I agree. I don't think the federal government should frame these things in terms of absolute $ amounts (I see the same thing in e.g. tax brackets and tax credits). The amounts should ideally be adjusted based on the COL and the dollar's purchasing power in the citizen's local area.