While the 22# is not a lightweight it certainly isn't a plane killer on this particular model. This plane was never intended to fly or be flown like a 3-D or IMAC ship.

If you have done all of the obvious things like moving the batteries and servos at or ahead of the cg then accept that the weight is necessary for the proper balance and go fly it.

If you can cram the ignition battery out under the firewall do that. And though some people will squawk, if it is possible even take the flight pack battery out there or as far forward as possible. As always do a engine off/engine on range check.
I have current aircraft that have both packs jammed together and have found no change in the range.