Can’t emphasize this enough. For the money, this is way better than a bathroom scale because of the remote reader. It’s also a good idea to get “calibrated weights”. Get 2, 45lb. barbell weights and find someone with a calibrated scale and record their weight. You can then calibrate your scale (know how far they’re off and do some math, mx+b right?). This is only critical if you’re one of those teams whose robot somehow always ends up at 119.8lbs.
There’s another issue and that is the official scales at the competition aren’t as calibrated as one might think. They do their best and their scale is the judge and jury. To avoid conflict the goal should be to stay 5lbs. under max so scale tolerances don’t bite you.