I understand why that test was done... was just saying it is not the same as on the car. Large jar of fuel at room temp vs very small q-jet sized container at a normal operating temp of an engine... 160-190, add a little for heat soak after shut off. That is the only real world comparison for a fuel evap test IMO.
Cant do a test like this here... my cars are in winter storage. I also mentioned that I dont think fuel evaporates in 30 mins or a few hours hours and that something else was going on for that situation.
I mentioned the temps for the example of my engines/carb, they run right at the T-stat rating, ~180 in the heat of summer city driving or at the drag strip for a lot of passes, some back to back. The car that does the evap/drain back the worst is the 500+hp E-head 72 firebird... with aluminum intake and no heat cross over, lol. 1978 Q-jet built by Cliff, carb leaks are unlikely, lines & pump are all relatively new, system will hold psi on the gauge after shut off for many hours if not over night. Car is parked in a garage, no charcoal canister system, just vented via the carb vent & tank is vented. Could have leaks Im not aware of but not worth it as my evap/return issues are very manageable, a few short crank cycles after sitting awhile or just drive the car every few days and its fine.
It obvious some do have this issue for whatever reason and they either live with cranking a little when needed or add a primer pump or go full electric. What causes the problems can be debated forever, but it does exist. Hope Shiny reports back if he tries a inline pump.