One can view it as a falsification experiment to quantum mechanics. Or in other terms to see what the range of applicability is. One doesn't alway know before where new physics is, most likely it is where one hasn't looked experimentally.
I often see the argument 'we should check because you never know' being used for supporting exotic science experiments. But I think it is too dogmatic.
Indeed, we have not tested experimentally whether launching andi999 into space will affect the muon g-2 anomalous magnetic moment. Although you might be very supportive of testing that hypothesis, I would sincerely doubt that it would lead to a discovery of new physics.
In the end this boils down to funding decisions for the sciences, which are invariably nuanced, difficult and political. Simply saying 'we should try because nobody else has' would convince only the most naive of funders.
I agree your suggested experiment shdnt be funded. I thought for the other one it is actually quite obvious. You have a quantum realm which has been confirmed by all experiments so far, and you have a classical world (objective trajectories), now it could be that there is a boundary where qm breaks down, or it could be that (when allowing for suitable coherence environments) that this never happens. I think you definitely shd try to push the (experimental) boundary on this one. Same like ppl check if Colombs law is really 1/r^2 (which is an even weaker case where one shd look).