How to scale beanstalkd?

Question

PHP

There was a question about the scaling of the beanstalkd queue server.
Infrastructure:
Docker (docker-compose) - php-fpm, beanstalkd, ...
the application generates events and puts them into a beanstalkd-tube. Workers in Go work outside the container and transfer data from the queue to a third-party service.
All this does not work under load yet, but there is a chance that beanstalk will lie down in the future.
Actually the question is how to scale beanstalkd?
HAproxy? And what to do with out-of-sync data?
Rewriting to IronMQ or to some kind of kafka thread is not yet possible.