I would suggest apply at the earliest. Even tomorrow if possible.
The reason is that even though under SDS scheme the process time given is within 20 days, there are many cases as of now where its been more than 20 days and no update. Infact over a month and no update (You can find many on current forum)
It may be that your file is processed under 20 days, but nothing is for sure and seeing the current responses from many students, the process time is actually taking long. Also, god forbid due to any reason a VISA is rejected, you would need time to apply again aswell.
So just a personal suggestion, file at the earliest.
Good luck