There is no way that environment needs anything other than you have in terms of power supply and distribution, I have flown plenty of jets similarly set up with no issues and on my uf and viper I wasn't really concerned about my speed when I deployed the flaps. Just fit 8911's on the flaps and be done with it. At least until you solve the mystery.
as a side note I was interested in power requirements before and on my uf I taped all the surfaces in place, fitted a watt meter to the battery and worked everything at the same time. The flash had 4 8711's and 4 8611's in it powered directly through a 12121 with life's and I couldn't get the total amperage to go past 0.8, flight loads are probably higher but how much!?