I think I'm done with Lingvist after next week. It's been about a month since I've seen a single new word. I do at least 100 words every weekday. I've done 725 words so far this week. I have 89% accuracy today.
Despite all this, the list of words to practice grows longer each day. At 2400 words learned, I guess I've hit a level where the system wants to repeat old words so often that I will continually fall further and further behind. How many more times in a row must I answer "tapfer", "stiftung", or "kloster"?
I checked these words you mentioned and with every correct repeat the next repetition time has increased further and further into the future (but not as quickly as previously). The next repetition time for most of these words is between 1 to 5 days from the last time you answered them.
That's great, except that in 1 to 5 days, they'll pile on top of the growing list of words to repeat. The algorithm will insist that I practice old words at an increasing pace. From email to Lingvist's support, I understand my account is affected by multiple algorithm changes over time. I wonder if I'm simply trapped in a corner as the algorithms changed around me.
Without any indication of forward progress and with the steady increase of words to practice day over day, I believe I'm done. It's been a fun ride, Lingvist. Thanks for all the fish.