Adding warmup sets

In my last workout, there was only one warmup set for each exercise. Even the first exercise - deadlift - had only one warmup set. This is probably because it was a light workout, but still I feel that one warmup set on the first exercise of the workout is too little, especially when the exercise is a heavy compound exercise. And even if the workout itself might be marked light, the weight might still be heavy. 

Naturally, one can do more, but it still would be good it one could add more warmups on the app at the very least, even if the AI would not offer more warmup sets. Especially the last warmup set might be heavier than the backoff set so taking extra warmups will affect the total load of the workout.  Currently, one can only add work sets but not warmup sets.