The current barrier is RAM usage of Jekyll/Ruby/polyglot. The RAM does
not seem to be deallocated, so it just consumes more and more per
language, until the whole process finishes;
There are three possible ways to fix it, not of them easy:
track down the cause of issue #78 above and fix it, so when a language
is completely rendered, the RAM is deallocated
replace jekyll-polyglot in fdroid-website with another localization
plugin that does not have this issue
replace jekyll in fdroid-website with Hugo, which is much faster