Possibly to do a "hard" delete using delete() method?

It looks like this might do what I'm trying to do:

$this->trashManager->executeInTrashContext('ignore', function () use ($node) {
  $node->delete();
});

At least it appears to be working. Would this be the correct approach?

Yup, that's the correct way to bypass trash and purge entities directly :)

Great! Thanks very much. It seems to be working fine. Cheers!