This is where purchasing a Keep Alive with the decoder comes in handy. It will make up for the consequences of not having all wheel pickup. The only think you must remember is let the keep alive charge up for a minute of so before you run the locomotive.
I have a brass Consolidation I'd love to convert for operation on my DCC layout. It appears the loco picks up right rail from the drivers and left rail from the tender. I know I'll have to isolate the motor from the frame, but my concern is that the gap between the last driver and first tender wheel pickups may be large enough that if I do have a dead spot somewhere (e.g., in an already-installed turnout that works fine with my F7s) the loco will stall. Does anyone have experience in this area, and am I being overly cautious/concerned? Thanks!