The other problem there is with a green notice over an SISii alert is a green notice and diffusion contain a lot more information on you this is copied from Interpols website
Notices and diffusions contain two main types of information: identity details (physical description, photograph, fingerprints, identity document numbers, etc.) and judicial information (offence with which the person is charged; references to the laws under which the charge is made or conviction was obtained; references to the arrest warrant or court sentence, etc.)

Your point about there being a risk assessment for Interpol notices is a good one. The requirement for a risk assessment to take place to isssue a Interpol is one made by Interpol rather than the uk. If the uk were to start issuing a large number with out the correct risk assessment Interpol would have to step in and do something. If a green notice has been issued against you incorrectly you can complain directly to Interpol and they will follow it up.

The biggest problem will be the new visa waiver system it will ask if you been convicted of a relevant offence in the last 10 years. However as far as I’m aware there is no such question on the schengen visa so that might be another option. There are two types of green notices they can issue one is a full green notice that any country can see and the other one is called something different but has green notice in the name disfusion or something like that they are the most common and can only be seen by the country you are travelling too. It does look more likely that police will start issuing a lot more green notices for travel to the eu.

As a consequence of Brexit, UK police and border force lose access to the Schengen Information System (SISII) and will have to utilise Interpol systems instead.

I know most people are not travelling at the moment due to Covid restrictions but hopefully that situation will change in 2021.

 I'm really interested to know what the operational instructions will be the Police forces / PPUs with regard anyone who has to notify travel. Previously, a section 36(2) alert was created on SISII for everyone travelling to the EU, regardless of risk level.  For travel to non-EU countries, there was a risk assessment to determine whether it was proportionate to raise an Interpol notice.

The question now is whether all alerts will be placed on Interpol or whether there will still be a risk assessment. Even if there is a risk assessment, will it be done on a case-by-case/person-by-person basis or default to that used for SISII i.e. anyone on the ViSOR database (which includes anyone who has to notify travel) was automatically deemed high risk.

Previously, for low risk offenders SISII was just an inconvenience and embarrassment at EU airports - it didn't actually prevent travel. Likewise, as low risk (albeit on ViSOR), travel beyond the EU was very straightforward. I can now foresee a situation where Interpol alerts are used as a substitute for SISII, which may not be an issue within the EU, but if they flag up at non-EU airports that will probably be a very different story.  It's one thing explaining to a Spanish border guard that it is only a discreet check and you have a legal right of entry vs having the same conversation with a border guard in Dubai, or Singapore, or Morocco or ...

If anyone has a good relationship with their PPU and used to travel, be good to see if you can get any feedback on how their procedures will change.