Argh, sorry to confuse everyone on this.
The downloading I'm referring to is for the raw METAR data from NOAA. Normally, X-Plane 11's real world weather system downloads this on its own, and some weather add-ons inject their own METAR data files in place of X-Plane's.
But, there are edge cases, for example XP10 or people who want to use weather add-ons that don't use METAR-based weather data and disable X-Plane 11's real world weather system. For these special situations, Real Weather Connector offers an option to download its own METAR data from NOAA and read from it, in exactly the same way we'd read the METAR data normally downloaded by XP11.
In that edge case, which is what "always" mode in RWC does, what's supposed to happen is we send a request to Gizmo to download that data in the background, and notify us when it's ready so we can read it. This way, the weather download happens without causing a big pause in framerate.
The problem is that NOAA changed their weather download server to use HTTPS instead of HTTP, which means Gizmo cannot download that data until it is updated to handle the HTTPS protocol. Since I don't know when that will happen, we implemented a "plan B" in SMP 4.8 that will go get that data itself if Gizmo fails to get it - but this comes at the cost of a performance stutter.
This all ONLY happens in RWC's "always" mode. There's no point in using this instead of XP11's weather data though, because it's the same exact weather data. It's just there to deal with these somewhat unusual configurations some customers have. And we still want Gizmo to be altered, because it offers a way to download this data without causing a performance stutter in the process.