If you stick with 7.4 or 8.4v
Then probably cheapest tweak for a slight boost
is maybe switch to deans on gun + battery
BUT don't go nutz on 9.6, 9.9 or 11.1v
without a fet - just keep it moderate
7.4v lipo stock wire and deans will
give a slight boost to trigger/ROF
All for a couple of quid
(As long as you can solder OK)
Little boost for little money, go easy on juice
and she will be fine without major modding