OpenWRT doesn't pack Python out of the box, so you need to install it, and have enough space for it, if you want to use Ansible. It uses a custom stack for configuration (like VyOS), so builtin ansible tasks won't always be so helpful. Configuration is not stored in a single place, but in several files, and it's easy to lock yourself out while testing changes: there's no commit-timeout, and there's no committing of changes, nor rollback. It's just editing random files, and restarting services.

I think there's a special configuration command that might fix some of the above issues, but I've been using the web interface (which actually does support committing and, to some extent, validation).