Currently MAAS client library only supports specifying a single target region controller endpoint.
For non-shared-L2 scenarios, however, there are multiple endpoints on different subnets without a shared VIP to hide them.
It should be possible to specify multiple target endpoints in a client library similar to how libpq handles this with PostgreSQL 10 (see https://bugs.launchpad.net/maas/+bug/1791957).
The problem is that MAAS is the first thing to be deployed on a given management network and there are no load-balancers or other infrastructure to provide means of proper handling of multi-endpoint scenarios.
Any python software that uses maas client would benefit from the multi-endpoint connection logic.
A specific example would be charm-hacluster which is used to manage address records with 0 TTL in MAAS in order to solve the multi-endpoint problem for MAAS API services. It does solve a problem by creating those records but it cannot connect to multiple MAAS region endpoints by using MAAS client as it expects a single target endpoint.