I think it’s more natural to ask “how might an agent behave differently as a result of believing an objective collapse theory?” One answer that comes to mind is that they will be less likely to invest in quantum computers, which will need to rely on entanglement between a large number of quantum systems that under objective collapse theories might not be maintained (depending on the exact collapse theory). Similarly, other different physical theories of quantum mechanics will result in different predictions about what will happen in various somewhat-arcane situations.
More flippantly, an agent might answer the question ‘What do you think the right theory of quantum mechanics is?’ differently.
[Edited to put the serious answer where people will see it in the preview]
I think it’s more natural to ask “how might an agent behave differently as a result of believing an objective collapse theory?” One answer that comes to mind is that they will be less likely to invest in quantum computers, which will need to rely on entanglement between a large number of quantum systems that under objective collapse theories might not be maintained (depending on the exact collapse theory). Similarly, other different physical theories of quantum mechanics will result in different predictions about what will happen in various somewhat-arcane situations.
More flippantly, an agent might answer the question ‘What do you think the right theory of quantum mechanics is?’ differently.
[Edited to put the serious answer where people will see it in the preview]