I just went through the account switch journey and I found my self having to do the partial switch purely because this is vaguely experimental and I didn’t want to close my old account. I would like it if there was, on the full switch, an option to choose which things to do like
Move all Direct Debits
Move all Standing Orders
Move your Salary
Close the account
I have just done exactly that. I didn’t close my old account as I plan to use it for cash deposits. I feel it went all pretty smoothly. I chose partial, selected which direct debits and standing orders to move over and that was it. I’m not sure it could be simplified?
Unfortunately it isn’t that simple 
Partial switches tend to be the most unreliable as although the banks contact the Service User (merchant), they don’t always update their records and set up a new instruction with us. As the bank you switched the instruction from will have cancelled their instruction, any DDs to the old instruction will fail.
Equally, we can’t switch a salary payment (Direct Credit) in a partial switch - this is mainly done by payment redirection which is a ‘feature’ of the full switch.
The Current Account Switching Service also has a few rules around how the options have to be displayed, and some very strict SLAs for actually completing switches.
See this would be really nice information to be given when you have to decide. This info isn’t clear when you’re prompted to choose which you want. Can I convert my partial switch to a full switch now?
It’s difficult to stop a switch once is has been started. If you’ve just submitted your switch then I’d get in touch with Monzo and ask if it can still be stopped.
I believe Monzo are looking at trialling removing the partial option as it causes issues
Additionally, as per my knowledge, only full switch is covered with industry standard seven day switch. With its best intentions Monzo will be relying on the bank from which you are switching out and other companies involved. Manual/partial switch, rarely, but can take up to 30 days on some occasions.
It is interesting to check out what switch guarantee does for you. For example, bank you switched out from is responsible for forwarding any credits sent to the old account (by mistake for example) for quite a while (if I’m not wrong, 3 years in some circumstances).
Yep and the redirection service can be in place indefinitely if you have a requirement for it. It’s actually the Bacs system that manages the redirects