But in a hypothetical real-time programming environment you could switch strategy at runtime (which of course limits your heuristics as it also has to be hard r

But in a hypothetical real-time programming environment you could switch strategy at runtime (which of course limits your heuristics as it also has to be hard real-time; that is probably the hardest part). E.g. you could have different code path depending on "load" (which is probably a vague term) and switch to different GC's implementations on the fly. What I mean is, that you always have hard real-time in the end. E.g. you could make your network service with a hard real-time limit of 100ms. On light load you serve all requests as you mentioned with ease, if load gets heavier you hit an uncommon situation (by definition, otherwise you would not be satisfied with soft-realtime) and everything changes, as you hit a rare situation. You could do different things, e.g. in case of a news page just serve plain text and get rid of images and while you are doing that you also change to a different GC that only guarantees 500ms.