This recently came up, so even though I’ve made this point in the past, I want to be really clear: metronome markings, the number of specified repeats and other elements in my scores are meant as suggestions or approximate guides. None of that is to be taken as rigid. The number of repeats, when specified (eg, 4x, 18x, can be considered as a minimum number of repeats. Generally, at least in the music I’ve written in the past several years, there is but one dynamic level, typically very quiet. Dynamics, unless one were to specify decibel level, are of course relative and subject to interpretation. I believe that when I specify a metronome marking, that too has some wiggle-room.
I am aware that as music performance becomes more rooted in technology, it will be possible, and even de rigueur, for performers to strictly adhere to a given metronome marking. I specify a specific metronome mark because the software I use generally requires it, or else a default tempo will be enforced. But I want to again indicate that I believe music is best when it is interpreted. I trust performers to realize their optimal, most musical and personal interpretations of new music and do not want to constrain such interpretation. I could go so far as to not specify any tempo, dynamic or even rhythm. But for me, composition is about choices, and I have chosen to specify some (approximate) guides as to my original conception of a new work. But these conceptions are not static; I might have indicated a certain speed for a piece, but when performed, grow fond of the tempo chosen by the individual performers. That doesn’t mean I will feel compelled to change my original metronome marking. Rather, I’m writing this as a general waiver to performers that they can use my metronome markings and number of repeats as guides as they see fit.