Weren't going to work so I switched to the style in the font:
╱│
∠--┼
│
And it really liked to give 7, 6, or 2 if I went in the left,upRight,down pattern.
I think I found out the trick though: if you make a sharp 4 like the font you get random results but if you just make smooth loop of it (almost looks like a tilted roller coaster) it gets it every time.
Even went I deleted the preset glyph patterns and spent 5 minutes re-training it for 1-9 my training pattern for '4' still didn't work. I tried drawing it 2 different ways. It's neat that you can train it so quickly with the hold-shift feature though.