my gut feeling is that redirects and reloads are in fact a memory issue of the phone. available > ram getting tight with many apps in the background competing, and not enough room for mini to > > expand websites, that are getting fatter and fatter.

Yes, that's memory management of Android. But UC-Browser takes 100M vs 70M of Opera-Mini, still working nice at 460M device (Android 4.4)!
It uses persistent service-threads, what could use Opera's developers, if they really care of real users.

@jackob11:
Let's not forget that file downloads put a lot of stress on Opera's servers and connections compared to just compressing websites, considerably raising the costs to run a free service to hundreds of millions users.

What for the downloads must go via Opera's proxy?!! It can't any way boost downloading (bottle-neck is last-mile of client, and any video/audio/installer is ultimately compressed unlike pages).
Downloader functionality is just using features of TCP in the client, here in Opera-Mini.

"by forum" (in-category) search in external engines works as follows:
"multi-word" "Forum feedback" site:forums.opera.com
to find this topic.
Works on Google, Yandex, mb others.
Though forum-name (category) mb not enough specific kw.