I wouldn’t recommend spending so long over single items. If I were reading a book, I wouldn’t spend 5 minutes sitting there trying to remember if I know this word or not, I would maybe take ten seconds, and then look it up. Sometimes it’s of course a word that I have studied in WK or Anki before, but I just take it as a sign that I’m quite shaky on that word, so looking it up immediately is the quicker option and also reinforces it again.
Same thing with a conversation; only that you don’t even have the luxury of thinking for 10 seconds.
That’s why during reviews I try to see whether I instantly recall something or not, and if I don’t, just mark the item wrong and check the meaning / read the mnemonic again.
Having to think for so long and not being quite sure is a sign that the item is still quite shaky, and would probably benefit from dropping a few SRS levels for stronger reinforcement, even if that of course increases your reviews.
I agree that rushing too much or feeling pressured by too many reviews is also counterproductive for leaning, and that sometimes it might actually be beneficial to take the time and try to recall a time/context where you have seen the word “in the wild” before, thus actually strengthening the memory. But in my opinion that should be 20 seconds max? But maybe other people think differently.