RE: balancing Tower 40 trainer?
I used a small bit of lead right under the vert stab. Worked great. No underpower issues because of it. I also moved my pack back but it wasn't enough. I am not a big fan of putting my pack in the tail. But that is only personal preference. One more extension is one more possible weak spot IMO. If needed, solder a longer lead instead of using extensions. Makes for a better piece of mind.