Multi-master PowerDNS setup

I’m trying to set up multiple PowerDNS hosts (masters), that will write to a Galera MariaDB backend.

I provisioned a HAProxy loadbalancer in front of the Galera cluster nodes and all the PowerDNS masters will connect to the Haproxy VIP. Are there any considerations I need for this, as in multiples writes to the same DB coming from multiple locations?

Also, I was thinking about setting up another Haproxy loadbalancer in front of all the PowerDNS masters and have NSedit (PowerDNS frontend GUI) connected to that. Would that be a good idea?