Hypothetical frequentists defined probability as limiting long run frequencies of hypothetical random infinite sequences, such as an infinite sequence of coin tosses. One argument against this definition is that these infinite sequences do not exist.
Richard von Mises, one of the main proponents of frequentism in the 20th century argued against this objection that e.g. instantaneous velocity is also defined as a limit, which does really not exist, namely as ds/dt for dt → 0. Or chalk lines on a black board are represented by lines without any width in geometry even though this is of course incorrect. But it is nevertheless helpful as an idealization and the question of whether it really exists is simply irrelevant, we shall judge the use of the concept by how it helps us do describe reality, and which predictions it allows.
Unfortunately I do not know too much about physics, so my question is whether you think that this comparison is valid? Just because there are other idealizations does of course not mean that everything goes. So is it a problem for hypothetical infinite frequentist that the infinite sequence does nor actually exist?
Furthermore do you have any reference to philosophical papers that deal with such idealized concepts in physics?