John Rumm wrote:

Would you be happy to use a smart phone or tablet to do the controlling?

Only if I could have one permanently kept in each room. But if I were to do
that, could I use them as (very) remote controls? How would that work?

Software permitting, perhaps I could have the input selection options
displayed as "Radio channel 1, 2, 3..." and so on (only with the actual
names) rather than "Amp input 1, 2, 3...") I should like that.

Bert