Didn't know that, in fact clicking around in the UI I don't see a way to change that so good on them for being friendly in this area.

PFBlocker seems to default to once a day.

To change when pihole updates you edit the cron entry at /etc/cron.d/pihole.

That's what I meant, it's buried in a config file. Not one of those things that should be surfaced in the UI that opens it up to abuse.