(I haven't unlocked the pushups yet, so I can't verify if this will work or not, but might be worth a shot for you.)I'd love to get better at push-ups, but not my making me do 10-20 of them at once which added a difficulty way out of alignment with everything else.
Depending on how the pushup rep is tracked, it might give you a pass if you do it on an incline, e.g. if you place your hands on a table or other elevated surface. If that does work, then you can either gradually decrease the incline, and/or increase the amount of pushups in this setup.
Personally I struggle a bit with some of the overhead stuff due to a slightly wonky shoulder that hasn't fully recovered. While I can cruise through some of the other exercises, I would definitely also like to be able to set difficulty a bit more individually per exercise. As it stands, I'm at difficulty 23, which is super-easy for some of the exercises, but increasing it will leave me unable to do some of the more shoulder intensive things. Customization would allow me to push myself a bit more on certain exercises while not being reckless with my shoulder.
Also, damn, the mountain climber things and squats are exhausting. Not really surprising, but still... Looking forward to improving in that area =)