Now that my card database is > 1M, it takes a while every time you press the '=' key.
One thing that might make entry time faster is to add cards on the number keys as well.
For example, if I press the 4 key, have it add 4 of the cards to the current deck. Then the whole collection will be saved only
once instead of 4 times, leading to quicker entry on larger collections, and less synchronization errors.