How does DO handle overlapping VPC IP space per customer?

Referencing https://www.digitalocean.com/docs/networking/vpc … it read that a given customer can only have one VPC using, say, 10.10.0.0/16:

VPC network ranges cannot overlap with the ranges of other networks in the same account.

Why would this limit be in place, if multiple customers can have otherwise-overlapping private IP space?

Does assigning a VPC to a different Project still suffer from the same cannot-overlap-IP-space constraint?

When the docs say “VPC network ranges cannot overlap with the ranges of other networks in the same account”, is that across all datacenters & regions? Or is it intra-DC/-region only? Ie, could I deploy 10.10.0.0/16 to both FRA1 and NYC3? The statement

We do not support VPC networks between resources in different datacenter regions

would seem to indicate overlapping private IP space could be handed-out to the same account, so long as it’s not in the same place. Is that the case?