Because there are troops challenges (like use 7 valk to get rewards, or use 2 golems to get reward), so I don't use CSV files anymore, because every time I have to change CSV file. I know there is something called "other" to drop the rest of the troops, but still it's a headache every time.
Custom train method sometimes faces issues, like making double capacity troops, or sometimes with making full troops, or especially removing troops when I made one dragon (which is not in my custom troops) to donate (and not to take to attack), ....
Also for option 3, I know it's SC fault, but it's possible to be implemented in the bot.
My biggest issue is option 1, and then 3. 2 is good to be done for increasing the bot startup speed.