There's that much of a chance of getting bad gas and that thin of margin in a gasser that it's catastrophic??
I'll bare my ignorance further, what is "bad gas"? Water in it or just not to the octane level it's sold as or what?
Obviously I've never even been around anything gas powered that wasn't stock. Never anything with any appreciable mods.
water in fuel is a biggy or picking up alot of trash in the bottom of a fuel tank due to a truck filling the fuel stations tank up prior to you filling up. plugs up your fuel filter, you go lean and boom. Cant say ive ever seen an octane issue. In mexico, octane is all over the place.
most cars have knock sensors will about 8-10* of timing swing availible and different levels of how fast it should pull timing based on the knock. they are quick to adjust.
Where 99% of the "running a thin line" happens is in the tuning. people "deaden" knock sensors, knock sensors are turned off or deleted, a/f ratio is ran in the high 12's or bit higher when under boost (considered lean depending on motor), timing is set high when the engine was cooler or outside temps were cooler, or a hard part was changed and tuning was not updated for it. This is all assuming you want the most out of it.