Oceniono na 4 z 5 możliwych gwiazdek

It would be perfect if we could set a default time to be sent the next day (extra/new option: Tomorrow), so that we can schedule emails going out in the morning the day after a holiday, for example. But in general I would like to be able to set a date/timestamp as a default, and then have the option to override or confirm it each time.

Ta opinia jest o wcześniejszej wersji dodatku (6.1.2). 

You can do all of that already. Please see the user guide. https://blog.kamens.us/send-later/