I solve the problem of speed by using a program called "the Amazing Slowdowner". It allows you to change the speed and maintain the pitch. It is great when you are doing something like this and you want to increase progressively.
My teacher had given me this piece to play as a duet and it is a lot of fun because both guitars get something fun to play! Many times a "duet" is where one guy gets the melody and the other gets the non-stop 1/8 note accompaniment.
Fun for the guy getting the melody. In the case of the inventions, it really does sound more like a musical conversation.
When the sun shines, bask.
Classical Guitar forever!