What you also need to be aware of, is the difference between manual Faster Payments (FP) and automated Standing Orders (SO).
This is why I moved from legacy bank to Monzo for my procedure to work.
Manual FP will leave your account at the time you instruct it. As said previously, while most arrive almost instantly, some take a bit longer
Automated Standing Orders though, in my experience with Nationwide and Santander anyway, leave on the date, or the next working day if a weekend or bank holiday.
So, if you set up SO to leave on 11th, hoping to pay a bill on say the 12th, if the 11th is a Saturday, the SO may not be processed until the 13th, and the DD, due on the 12th, will also be deferred to the 13th, leaving you back to the situation of at what time the credit or debit takes place.
If you have DDs that close to income day, may be worth trying to move them.
As a matter of curiosity though, if your bills (assuming DDs) come out that close to income day, why not just have them paid from your income account.
I don’t know how you work your finances, so your method may have a sound rationale behind it, or suit your own purposes. not judging