Originally Posted by GinFizz

But seriously, why are you considering this option? The price via Helsinki is coming out at around 6000 USD - and you will need to take tests in both the UK and Finland.

I am pretty sure that moondog already mentioned in a private message to you the option to travel from Rome. That is priced at only (!) around 4000 USD for late Sep and October - but for you, as you have an Italian passport, this means that you could probably use this route without the need to take any tests in the UK. Just fly to Rome, stay there a few days then take the tests and then fly on to China.

Unless there are any questions on the health code form that ask where have you been living, they will just see someone applying from Italy with an Italian passport and not consider that you may have arrived in Italy a few days earlier after living in the UK.