Mixed Difficulty Days

If it wouldn't interfere with the muscle-building algorithm/research behind the application, it would be nice if there were an option to have easy/medium/hard days intermixed.

Instead of having single days for each level of difficulty, every day a third of your exercises would be on their easy days, a third on medium, and a third on hard.  You could still have each exercise go through its proper progression of the difficulty levels, but your whole body wouldn't be so overwhelmed on hard days.  It would also make scheduling easier.  Some days my workout takes 30 minutes, others 90.

It feels as though this would also help me progress more quickly.  On hard upper-body days, I'm certain that my own overall exhaustion is taking away from my capabilities on the last 1-2 exercises.

For me at least, it would also help mentally.  It is much tougher to get up the motivation to hit the gym when I know I have a hard day facing me.  If every day had a few easy, a few medium, and a few hard exercises, it would be mentally less daunting.

Finally, it would also open up other exercise options.  I tried switching over to the push/pull/legs plan but had to immediately switch back to upper/lower.  There is just no way I'm going to give it my all on deadlifts and squats on the same day.  Both exercises are simply too draining on a whole-body level for me.  But, if one were on easy and the other hard? Then it would be possible.