I thought you had a typo at first, but you've done it again. It is WeeWX not WeeMX.
Yes, there are several WeeWX driver extensions for the WLL. You do not need a paid subscription to get all of the live data from the WLL. One of the benefits though of the optional WeatherLink.com subscription is to get archive data. But if you keep your WLL and WeeWX system up and running 24/7 (batter backup ..etc.) then you'll likely not need the Weatherlink.com archive data ever. You can efficiently run WeeWX on a Raspberry Pi to optimize your battery backup requirements.