May I suggest your plane needs to go on a diet? With 30 ounces in the nose my guess is you are over 13.5#. My YS140L with Slimline Pitts muffler provides unlimited vertical on my H9 Cap 232 with an APC 17X8 prop at 12.5 pounds w/o fuel. You may want to rethink your dual elevator setup and twin battery packs to reduce weight. A good single forward mounted servo can drive the elevators. The trick is to get straight runs from the servo arm to the control horns through two Dave Brown pushrods. Or try two servos forward mounted through two pushrods. This should eliminate a lot of nose ballast.

The 16X12 prop is intended for pattern style planes....much different from your 25% aerobat's performance needs. Try more diameter and less pitch...

Joe