You should always use space repetition, as it's a proven method for increasing retention over time. That said, you can configure Pleco to alter which cards it includes in a given testing session, and how it displays those cards to you.
Card Filters
The most helpful filter is probably Score Filter, which you would typically use it to force the selection of cards that have a low score (i.e., cards that you do not know well). For example, by default the SRS algorithm may select 400 cards for review, but Score Filter would allow you to filter our the cards you know well (i.e., a high score), and focus on the cards you don't know well (i.e., a low score). I use this setting the most when drilling on specific categories of flashcards, like vocabulary lists for tests. You can also try Record Filter and History Filter, but Score Filter is probably all you need.
Configure Score Subjects
This allows you to configure what flashcard information (i.e., headword, pronunciation, definition, audio) is shown, based each card's current score. Here's a configuration I often use:
- Initial: Characters + Pronunciation + Audio: this is used for cards with the lowest score (i.e., a card I haven't studied or I don't know well) and it shows all the card's information.
- Step 2 (Score >= 200): Characters + Audio
- Step 3 (Score >=400): Characters
- Step 4 (Score >= 800): Definition
- Step 5 (Score >= 3200): Audio
Essentially, as the score for a card increases, Pleco shows me less and less information. By the time I know the card very well (a score of 3200), only the audio for the card is played, and I have to recall the characters (I enable 字 and write them on the screen) and definition. (Note: I usually enable "Audio" only when testing on very specific and narrow categories of words (usually flashcard categories I create to accompany a test I'm reading). I do not suggest enabling audio only when testing on large numbers of flashcards, as Mandarin has far to many homophones to make this practical).
Pleco has other flashcard settings you can tweak, including those in the Card Selection area, but I suggest you leave them at their default values. It's also worth noting that the flashcard functionality has been rewritten, and we should slowly see the new functionality in upcoming Pleco updates.