That charger (VC2) doesn’t have a discharge function, which is the only real way to determine capacity.
It shows how many mAh is put into the cell, which does give a fair guide on healthy newer cells but maybe not so much on older ones.
3.8v should be a fine rested measurement for storage of cells though.
Don’t worry about it too much, you’ll be wanting to replace cells every 3-4 years anyway.
Maybe the Opus BT-C3100 V2.1 would be better for you.