I dont think Armorall burns at all! I have heard of guys doing some very weird stuff, but adding Armorall in the fuel just sounds totally bizarre. I think it would detract from the fuels performance just as allowing water to contaminate the glow fuel would do. Once the water content reaches a certain point...which is a very low percentage, like 2 or 3 percent or less...the fuel no longer fires at all.
Beyond all that...the fuel manufacturers...at least the good ones like Morgan Fuels, Omega, and Cool Power...have already added a defoaming agent to their formula. If Armorall worked better...dont you think they'd be using it?
As a final note...I have been hard mounting my fuel tanks for years, and have never had any issues with foaming.
You may have a fuel draw problem, and maybe a perforated fuel line, but the talk about true fuel foaming as the source of a problem seems to be a throwback to the old days when tanks HAD to be mounted on foam rubber to isolate vibrations. A bit like old NiCd batteries of 25 years ago showing what they used to call "memory effect". ...Also now relegated to ancient history.
I wish you luck in tracking down your gremlin, but I'd suggest NOT adding anything to a reliable fuel manufacturers mix.