Changing from traditional accounting to cash in cash out

golden

I have used traditional accounting for many years and now I am going to be dragged into MTD I realise that cash in cash out could be a better option for me.
I rent out houses as well as have self employed income.
Some if not all software companies such as Hammock also do only cash in cash out and I am wary as well of having tight dead lines for quarterly assessments and not wanting to twiddle around doing appropriation when everything is going to be expected to be instant so I feel it will be quicker and simpler to do cash in cash out all round.

This is new for me so I believe that if rent is due in say on the 1st of April but isnt paid until the 6th of April or later that the rent on a cash in cash out basis will be written into the tax year from the 6th of April as that is when it was paid?
Some rent is paid but doesnt appear in my account until later... so do I account for it when it is in my account? Or when the agent receives it?
I would be grateful if someone who understands this system can help me to understand this more as I wish to comply fully and not get anything wrong.
Many thanks