WAL is reliable, but Publish/Notify isn't. You'll lose messages with Publish/Notify if you aren't listening for them.

If you just use notify to tell listeners “there is work in the queue to grab” can you still lose messages? I’ve always seen it implemented where workers have to go and claim items (transactionally), not just wait to be pushed them.

No, that way is safe. Just make sure that your workers also check for items in the queue when they start.

this is exactly what I meant - WAL is your friend.