Condensation of a small DSD system with two alternative condensed reactions. Resting macrostates can contain more than one complex, e.g. RM1 contains two resting complexes: {RC1a, RC1b}. Whenever a resting macrostate contains only one complex, we use the same name for the macrostate and the complex. As discussed in the main text, the fate of a resting macrostate is the resting macrostate itself, while the fate of a transient macrostate (here: TM) is the set of resting macrostate combinations reachable via fast reactions. After RM1 and R0 react in the detailed network, the product of the condensed reaction is not yet determined, a phenomenon sometimes referred to as ‘delayed choice’.