It's very helpful to be able to adjust before starting! I sometimes have to study on the go and therefore in settings that are less than ideal for studying/focusing lol, so being able to choose to do untimed drills for those times was perfect.

Timed drills are important, but it's not always feasible to do them every time.

it could be burn out, always give yourself a break :)

Love this feature! I thought of a possible improvement; I noticed today when I logged in the streak automatically went up, but I think it would be more motivating if it only went up after doing a drill or any kind of studying