The days quoted are the difference between the application date...

The days quoted are the difference between the application date & the sales date, give or take a day here & there.
Some sales took more than one day but the days are pretty close.

Re manually
There would be an equivalent application deadline & likely delay between the shares being issued to the custodian & being applied to individual accounts.
It all depends how efficient the custodian you choose is.
The big difference is that you can sell when you like as your volume will be peanuts compared to SPP Harvester.

I personally would not 'speculate' & hold longer except in exceptional circumstances.