There is no AMA rule regarding "Hot Gloves" for Mouse 1, so it must be a local rule.
The spring loaded tank vent as shown in that article does allow faster filling, mostly due to the size of the filler tube, but more importantly, allows the tank to be a "Uniflow" system which definitely produces a steadier engine run.
I tried a uniflow system on my Mouse 1 entry for the first time at the Dallas contest, and it made a big difference in engine run quality. It also cut clean at the end of the tank, without the usual lean out or sag the last lap or so.
Les