Super Alpha Open Rocket Results

I loaded the BT-60 based Super Alpha into the Open Rocket software to check it's stability and predicted altitudes.

I was concerned if nose weight might be needed with a 24mm D12-5 engine installed. The Super Alpha was designed for 18mm engines.

According to the software simulations,
The 18mm C6-5 altitude is 696 feet. (Super Alpha with an 18mm mount installed)
The 24mm C11-5 altitude is 622 feet, less than the 18mm C engine!
The 24mm D12-5 altitude is 1076 feet.
The 24mm D12-7 altitude is also 1076 feet.

I didn't think the the C6-5 engine to get a higher altitude than the C11-5.
I would expect the D12-7 would get a better altitude over the D12-5 - it should coast longer and go higher.

This probably isn't accurate, I'm new to inputting information into a simulator. I may have left something out.
Still, interesting results.