If my ISP is trying to reduce bandwidth costs in the way you describe then that may be an issue but what I am observing here doesn't quite seem to fit with that explanation.
Of course it's your ISP trying to save HIS bandwidth costs (and even putting you under a quota) by doing some local caching.
As usual, the issues are more complex that one might think. To make downloads even MORE reliable, not only we use Cloudflare, but we have TWO mirrors, and the installer will choose a different one at each start, that's called "load balancing".
Obviously, the original files on our mirrors are identical, and I'm fairly sure that now, after some days, Cloudflare has replicated all over the world but, if your ISP does some caching depending on some expiry time, they might have some files cached from a previous version coming from one mirror, but correct files coming from the other ones, because the expiry times won't match since the first downloads you triggered didn't happen at the same time. The mirrors are not treated equally, there's a primary one and a secondary one, and the secondary one is used only if the primary one has issues. That's why you think files are coming in different versions "at random".
Your continuing requests of downloading again and again, would just make the caching strategy to persist because, the whole point of caching is that, when a file is requested over and over in a short period of time, it's a prime candidate for caching. Instead, you only had to wait for the cache expiry time your ISP set to lapse, so it would have refreshed his local files automatically.
A way to defend yourself against bad ISP policies might be using a VPN. That would skip over any caching your ISP might have in place, because with a VPN the communication is encrypted between you and the host you are downloading from, so your ISP cannot possibly know what you are downloading, hence cannot use any caching.
The whole point is, again, nobody should require to download the full installers so often and particularly not immediately after an update because the Live Update can update everything and the new one is exactly THE SAME ROUTINE ( it's the same code with a new interface ).
The one and only case in you might require a NEW installer, if it's a major version of the sim comes out so, for example, when P3D5 came out, an updated installer was required, because the previous one didn't recognize P3D5, but that's it. If you just kept the first installer we ever released for P3D5, the Live Update would have brought you with full updates up to this version, and the next time you'll need to download the installer again, would be if a new major version would eventually came out, like P3D V6.
