But is that solving a symptom rather than solving the problem? Whatever low pressure existed to cause the BVM UAT to collapse, still exists. If the UAT collapsed then there is a restriction somewhere in the fuel feed to the UAT or the air vents to the tanks, the fuel pump will have to be straining against that restriction, and changing to a hard bottle UAT doesn't change that.
The new Wren 160 uses 3mm tube on the pressurised side from the solenoid valve to the engine, I haven't been hearing any reports of it suffering flame-outs. I agree with what you say Olnico, about the need to look at using larger diameter tubes to slow the flow rate and the drag of the fuel that the pump has to work against, but how does the Wren 160 experience fit in with that?
Harry