I managed to transfer 3 whole box except these 9 Zesserboss mentioned that will cause error.
Still have crashed at the end of saving, but logged in again and they already in the bank.
Also tried to transfer a Sirfetch'd after customize some stats, it was success but also crashed at the end of saving.
After transfer I checked and noticed the only thing I can't change is the Ability, I changed Ability to Scrappy and in save file still appear as Scrappy but after transfer to Home the Ability change to Steadfast.
Anyway we can change the Ability?
Also can we make gigantamax?