The objection in question ignores Bostrom's basic argument.
Irrelevant. The objection is orthogonal to Bostrom's argument, but could absolutely refute it, if valid (which I don't believe, more below).
Bostrom argues that if simulation is possible, it must eventually be done which means there probably are a large number of simulated universes and only one non-simulated one (I'm simplifying here, but that's the core of it). If a counterargument demonstrates that there is some reason our observed physics is incompatible with any possible simulated physics then Bostrom's argument becomes irrelevant, because we have proof that our universe is not simulated, regardless of whether simulation is possible or whether it has been done. Or, if the weaker counterargument that our observed physics is incompatible with any reasonable simulated physics, then Bostrom's argument becomes weaker, though it's not refuted because one could postulate that the creator of the simulation chose to create an unreasonable simulated physics in order to fool any intelligences that arose within the simulation and looked (note that this latter argument also works against any proofs of the non-existence of any form of god who has some reason to demand faith -- you can always say "Yeah, but god made it that way so that we'd have to take his existence on faith.")
However, I think Hossenfelder's argument is flawed because she's making a crucial and unjustifiable assumption: that any simulation must necessarily simulate every detail of the simulated universe, i.e that the simulation in question must be a finite element model. Not only is there no reason to make this assumption, there's every reason to assume its opposite, because it's clearly more efficient to simulate at a higher level of abstraction. In that view, the weirdness of Quantum Mechanics actually supports the simulation theory, because we can surmise that the simulation does not in fact model elementary particles but only their aggregate behavior and what we're actually seeing when we try to look very closely is a predictable result of this incompletely-detailed simulation.
Note that I'm not saying I think we live in a simulated universe. I think it's probably impossible to know, but to the extent that we think we might be able to search for artifacts of the simulation, QM's very weirdness is probably the best artifact we have to support the notion, not a refutation.