Above is a half-baked Mi Zige examination paper.
6 cm and 7.5 cm squares can be written in block letters.
10 cm grid can not only be written in block letters,
You can also practice inch letters with small squares.
Calligraphy, whether it is better to practice big characters or small characters, depends on everyone's preferences. There's no need to force it. You can practice whatever you like. Practicing calligraphy is a long-term tempering process. It's not difficult to practice big or small characters, but it's important to keep practicing.
But when you practice small letters, it will be easier to practice big letters.