question

From personal experience, don't open multiple giveaways with the same game.

If you have many keys of the same game, create one giveaway for all keys instead of one giveaway for every single key -.-

Do not give more than 24 keys at a time in one hand

you mean to create at least 100 giveaways?
every 3 games you deliver give you +1 slot. that's one way to increase your maximum amount of giveaways at once.
the other is to ask support with a ticket.