Have you tried one to layout? I tend to "elongate" my second back-handspring, which is good for two to tuck/full when your knees are more bent and can compromise it. With 2 to layout, if your second backhandspring is too "long", your body takes off at an awkward angle.
Try one to layout, then two to layout. Feel the difference in power. Have someone film it from the side and look at the difference between your first and second back-handspring. If it's noticeably different, try to make changes in your second one so it's more like your first.
I'm having difficulty wording this to make sense, but differences between the first and second back-handspring will change the height you get and ability to set. Let me know if you have any other questions about it!