My piece Gesleten piano has lamps, tapes, and a broom. It is a piano piece with “simple” added objects; everything is fully notated on a very clear score.
The usage of materials is organic and simple but the reality of life is much more complex. Explaining to performers extra-musical actions takes a lot of energy and rehearsal time. It is easier with percussion players because they are used to deal with objects (and carrying them!)
The usage of extra-musical resources on chamber music will improve in its implementation with the practice (in fact is already improving a lot!), but we, composers, should think and re-think the usage of each extra material we employ. In the concrete practice (rehearsals, transportation, stage set up, explanation to new musicians, sharing the piece with other pieces in the program) each gesture out of the ordinary becomes exponential. Anything we think is complicated, will be very complicated. Unusual is generally not practical.
We can write, of course, whatever we want. We can write a string quartet with only one single note of a flute, for example, or we can write a long piece for a triangle that includes 5 seconds of timpani music (I am thinking more about transportation than in the music). It is like buying a very expensive dress to use only one time. .. why not? These beautiful extravagant and “non-purpose” gestures can be very relevant if we want to go that way. My point is that composers should acknowledge the complexity of apparently simple things when included in the usual practice. Not as a restriction but as an act of responsibility, getting to know our musical materials and their possibilities better. Working with props and extra-musical actions the same way we do with the traditional practice.