The jury's out on this.

I've thrown together the gadget to trick Tru into thinking she's a bit rich but I'm a gunna have to take her for a fair drive to get a better idea of results. A quick test drive didn't result in any problems but whether it saves any fuel is still in the maybe stage. I certainly wouldn't recommend driving hard with this change but since I drive like old aunt Agnes I don't expect reliability problems, Ford did put better valve/valve seats in the egas version than the petrol one.