If a project is serialized on a 64-bit machine, then deserialized on a 32-bit machine, then any usize that's larger than a u32 will (?) cause an overflow. If we want project files to be portable, then this is a problem.
Counterargument: we're not checking for overflow on anything that's a usize/isize, so if it's possible to get a number larger than 2^32 on a 64-bit machine, then the same operation would have failed on a 32-bit machine long before we got around to saving the project.
Almost certainly an academic issue.
If a project is serialized on a 64-bit machine, then deserialized on a 32-bit machine, then any usize that's larger than a u32 will (?) cause an overflow. If we want project files to be portable, then this is a problem.
Counterargument: we're not checking for overflow on anything that's a usize/isize, so if it's possible to get a number larger than 2^32 on a 64-bit machine, then the same operation would have failed on a 32-bit machine long before we got around to saving the project.