For offline software I wouldn't consider it a problem, but for something that connects to the internet I would want it to have the latest versions of its dependencies.
It looks like the dev has been updating their funding details recently, hopefully they have an update planned.
Firefox's default in-built download manager is hot garbage. It is so much more reliable to download multiple large files at once with a resource-friendly download manager.
Unfortunately alternative are closed source (ADM , IDM ) , I've heard that free download manager was open source but even if it's still , I won't recommend it because it was reported that it redirected Linux users to malicious links