In regards to your earlier post about light novel speed, it does take 1-2 months per novel to translate the text because these translators take their time to better localize than a fan-translation (guess which one of us has actually translated a novel before). There's utterly no way that any publisher would say "I'm going to have our translators work on this latest volume 34 books ahead and ignore the previous volumes!" because you'd alienate potential customers who haven't read the earlier novels.
Though that is Crunchyrolls exact strategy with manga that are midway through.
And of course I'm well aware that a professional non rushed translator turns out a better translation. Of course even with 'better' translations theres a range of issues surrounding that that I wonder about in terms of how Yen translators approach material compared to the general consensus of fan translators. Like what gets left in the Japanese and what gets localised. Such as name suffixes and honorifics. Hell I don't much want a localisation, just a translation. I don't want things like kotatsu translated to heater or food names changed to something thats common in the US.
You have to start at volume 1 and work up there. Yen heard the complaints that novels were coming out slow and so they increased their pace (even moreso for Index) and yet people still go "It's not up-to-date, so I'm not buying." It's incredibly self-defeating as a fanbase to think that way because you're just dooming the franchise to failure and you'll never get what you want.
It is understandable, but it puts folks who have been reading fan translations but would rather pay authors 'something' in a bit of a hard place. Especially when it comes to super long series like Index.
If I'm someone who has read all of Index and read up through volume 10 of Next Testament is my only option to buy the Yen books and wait for yen to hopefully one day catch up to that point, which may be 7 or 8 years from now?
Seems like the best moral option continues to be buy from amazon.jp and then read the fan translations as they come. At least if you are unwilling/unable to learn to read the Japanese edition.