I like your idea Don.
As for leaving 30m phone greyed out - this would be OK for USA and many other entities, including ZL.
However some entities, e.g. VK, do allow operation of Phone mode on 30M so they might not want it the way you do!
For this reason, and maybe others too, it would be desirable to have a "user choice" on what was or was not greyed out.
Of course we are only considering DXCC, so the grey out function would also need to be award specific too.
Sounds like a real can of worms for Dennis...but he may already have an answer.
73, Cliff