[Feedback/Lament/Request] "Difficult words" mechanics

Hi all, I’m trying to pick up some French and I use the app once every few days …

Firstly, I’m a pro subscriber and have been for a while… Memrise iOS doesn’t let me remove/add words to difficult words , which is so frustrating and it really should’ve been implemented by now…

Secondly, I’m frustrated with the mechanics itself … If I get a sentence even slightly wrong, even ONCE, Memrise decides that it’s a Difficult word…??
Especially in a classic review… Where i want the classic review to help remind me of what I learned earlier and may have forgotten, top keep my memory of words and sentences fresh … It really shouldn’t feel like an exam imho, but it does…

Take for example a 6-word sentence in French I was reviewing for the first time after 3 weeks… I used “une” instead of “un” and the sentence was immediately marked “difficult words” (pic attached). How does that make any sense at all??

Even when you click to get more info on “Difficult words” it clearly states “if you get a question wrong A FEW TIMES…” . A few is described as "not many, but more than one”. This, added to the inability to mark/unmark difficult words, really makes me feel pressured to be right, rather than learn gradually from my mistakes, like there’s no margin for error while learning a new language?!

why doesn’t Memrise iOS let us remove/add words to difficult words ??? @MemriseSupport