Select all button for select and linked record fields

I might have a niche case here but it would be really helpful to have the ability to toggle a select all button on select drop-downs and also linked record fields.

My specific use-case is that we are adding suppliers into the system and we select which countries they supply (the countries are a linked record collection rather than a select field as there’s a lot of other pieces to the app which are also linked to countries). This is all fine for most suppliers as they’ll typically only serve a few countries, however there are some instances where a supplier will supply all countries and it is quite painful to select each individual country one by one.

It would be really helpful if we could have a select all button to select all the potential options, this would even be helpful in instances where a supplier supplies 95% of the countries as you could then select all and untick the few that they don’t supply.

I’m sure there are plenty of other scenarios where people have large multi-select/linked record fields where it would be a big time saver to select all.