i am bothered by two things in your question. First the assertion that it must be left on constantly. Maybe, but i do not find this to be true with my own designs. Rather i find a HUGE change in the first 30 minutes, a smaller change int he net hour and a decreasing benefit thereafter -- but your experience my very.
I will say that many of my designs have the low-power circuitry on 24x7 with no provision to be turned on and off - because it does improve sound ( and IMO, longevity). But the power hungry output stages....my advice would be - experiment and list. Do it multiple times since perception can be affected by many environmental influences.
My second concern is that it gets marginally too hot to touch. Maybe i'm just conservative, but that sounds like poor design to me. Nothing i design runs too hot to touch.
Do your own testing.
I will say that many of my designs have the low-power circuitry on 24x7 with no provision to be turned on and off - because it does improve sound ( and IMO, longevity). But the power hungry output stages....my advice would be - experiment and list. Do it multiple times since perception can be affected by many environmental influences.
My second concern is that it gets marginally too hot to touch. Maybe i'm just conservative, but that sounds like poor design to me. Nothing i design runs too hot to touch.
Do your own testing.