Harmful to set sync_trait multiples times for the same pair of traits?

Is it harmful to redundantly setup the same pair of traits to sync?
Something like:

my_obj.sync_trait(name, other_obj)
my_obj.sync_trait(name, other_obj)

I ask because I'm doing this in a context in which it isn't obvious
whether or not it has already been done (depending on how the user is
interacting with the app).

Thanks,
Alex