I think water flow is overrated. I'm only running HOB and no powerheads. Remove the 11" catfish, could be it's not comfortable that it can be a meal itself. Get some tankmates it can school with. i.e. Acestrorhynchus barracudas.
Water flow has nothing to do with ATF eating. Imo its just all in the keepers head to try and mimic the ATF's natural environment. In my experience, eating will depend on the species. Goliath seem to be the slowest and harderst to wing off live. VATF are hungry bold little monsters and will except a wide range of foods. I had my old guy eating zucchini that was meant for the pleco.