Re: "Too tight" base/stem grommet
The black rubber grommets are usually on the larger size of their size groups (if that makes any sense)
One temporary method to fix this is a lubricant, either a cooking oil or even a silicone lubricant works (system JO works perfectly and lasts a while...dont judge me)
A permanent solution would be to sand the grommet down liked mentioned, however this is a messy process, you will have little rubber bits everywhere, don't do it on carpet.
Lastly, you could try something getting another grommet, like a silicone grommet, however those are more prone to tearing, or acquire a clear rubber grommet, they tend to be thinner than the black grommets.
"blu mist rulz dawg an that stuff ain't like it an if youz don't agree you bez a shithead yo" - Hajo Flettner