thanks for replying!
well, this is exactly why I wrote this post - after increasing the word spacing I still see the timer set at 1 minute for the Koch lesson. so, it's kinda too short vs the default zero spacing with a full 1 minute drill. :-)
When you click the settings wheel and shift the wordspacing in "lessons" to the right, up to 6 times normal is possible, you will find out by watching the real time seconds on a watch, or looking at the used/total time at the right op the settings wheel, that the total time it takes to complete the exercise is automatically prolonged.
Just what you propose was already implemented.