My experience is that for 2 years I didn't really pay attention to tones when I did the SRS repetitions.
Honestly, it didn't matter too much in the every day life, most people understood me anyway and I wanted to focus full speed on expanding vocabulary.
But then I decided that I had to do better than that, so I started to include the tones in my answers for the SRS repetitions.
What I mean is that before, I would put "perfectly remember / remember / barely remember" even if I had the wrong tone but that I knew what the character meant.
Now, I will put "forgotten" if my tone is wrong for single characters (if the flashcard is only 1 chinese character), and if it is multiple characters and I have 1 tone wrong inside, I usually still mark "correct" but then I immediately divide my score by 4.
The immediate effect is that you end up with much more daily flashcards as you have a lot more wrong answers.
But it really worked. After about 1 month I could remember almost all the tones of the characters I already knew.
// Francois