I like the idea of selecting an altitude above your aircraft as opposed to 1000'AAL. To take it a step further it would be even better if you're able to select the GA altitude.
I disagree with a "random" altitude above the airplane. You have thus eliminated one of the warnings that you are too low for the conditions. Even the Missed Approach altitude setting is a bit premature...
"GA altitude" (i.e., DA) is reasonable IF you are in a reasonable configuration -- speedbrakes in, power up, V/S <1000 FPM. If you're still trying to achieve the G/S from above, that's too low!
The min SOP "stabilized approach" altitude gives you the margin of safety for virtually all unplanned situations -- at 1000' AAL, you can recover from any reasonable configuration. It carries the bonus of being "legal" if you are ever officially questioned.