I'm doing some FMQ and I'm stopping and starting a lot as I jump around outlining flowers as part of the process. I keep having trouble pulling up the bobbin thread periodically, but just enough to be a real nuisance as I keep thinking the thread is out when its not. Its a vertical bobbin and I keep wondering if one of these "genie magic bobbin washers" would help? Is that one of the things they solve in FMQ? Or maybe its my bobbin tension needing some fine tuning? Please expand on how do these washers improve your stitching. Thanks!

The main purpose of these washers is to help with FMQ. I wouldn't say I had a problem with FMQ before getting the washers, but I do believe my stitches are nicer with them.

For some quilters and some machines, I think they can make a world of difference in FMQ. For others, not exactly a "must". But hey, they can't hurt, they might help, they're not overly pricey, you get several in a pack and each one last a looooooong time -- so why not?

From reading the posts here I'm guessing they serve the same purpose as the felt washers on thread spools, just enough drag to slow down the fast spin you can get when starting.
You can do the same thing re: bobbin area by adjusting the tension on the bobbin.