I can see that on the Roadmap Anki export and import is to be implemented, which will make me able to use the full scale of Anki features in addition to Logseq if implemented correctly.
my suggestions are:
1)Having multiple Types of Cards: one liner, multi lines, image occlusion type, basic and reversed, and so on.
2) the ability to create those types according to a regex expression insead of #card. for exampel :: for a one liner card. even a line break can be used to make multiline cards instead of #card making everything a card.
3)Image Occlusion with the ability to hide the boxes, in case someone wants to just read his notes.(view mode)
4)Cloze shouldn’t be hidden while reading document, it only should be hidden whilst reviewing the cards. also the ability to change the trigger for cloze would be appreciated as well as a shortcut.
5)Ability to remove empty cards (cards with no back content)
6)Ability to suspend Cards,bury or disable cards, whilst viewing the cards.
7)Edit later feature
Edited:8) Better view of cards location during reviewing them,as in include parent bullets and Document Name cards exist in, as well as the ability to provide global tags for all cards in a Document.
I posted something similar in January of this year, here.
I would summarize the request to do something similar to what remnote does, as @faldor20 comments above.
Image occlusion cards
Concept/property cards (similar to remnote)
Make responses more than just text, like voice memos (this can be useful for learning pronunciation in other languages)
Create cards using something other than the hashtag #card
Possibility of viewing cards by topic, in a simpler way than simply using queries. For example, view the ones on a particular page. Although this probably goes hand in hand with improving the namespace/folder system, someone was already talking about it here
Anyway, I do agree that the flashcard function can and should be substantially improved, and there are good examples with Anki and Remnote as references.