The only thing I didn’t 100% love about the Hardtail vise was the bumpers to dampen the handle. They are a bit too big for my liking, so I replaced them with these which fit much more snugly and won’t fall off the end of the handle. Spoiler alert: They are just sections of 5/8" ID hose cut and stretched to fit.
Video Here: Fireball Hardtail Vise Upgraded Handle Bumpers - YouTube
The outside diameter of the upgraded bumper is 1.0625" when installed, so if you use a cheater bar on your vise, it should be at least that large of an inside diameter. I use a Harbor Freight 3Ton jack handle as my cheater bar, and it fits perfectly.
If you’d like to support my ingenuity, you can buy them here 
Upgraded Handle Bumpers for the Fireball Hardtail Vise – BD Products