Yes... if the rocket experiment goes bad... it can go very bad. (which is one reason why I suggest tests with lower power rockets before the big one.)

An E-class rocket can do a whole heap of damage. A B or C engine is not going to do nearly as much damage (if it somehow manages to break free of the model) nor is it going to make as much difference to the controllability of the model. (note my experiment's results above...)

You will need to angle the thrust to push the nose of the trainer DOWN a little. (mine was straight, on a .40 size trainer, and overpowered full-down elevator with the larger rocket engine.) HOw much? well... when the smaller rocket engine results in the trainer not pitching up... then you probably need a little MORE angle with the larger rocket engine. (you can extrapolate a reasonable guess by going up in power a little at a time...)

A 0-0-0 Pattern design might do OK with a 0 thrust angle rocket boost... I might even try it...

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typos [&:] probly more that I didn't see.