MySQL Trigger: Can you turn a query updating multiple columns to multiple queries where each update one column?
I suggest that using a VIEW is the wrong starting point, and that TRIGGERs are just adding complication.

Instead of using Views and Triggers, have a "database layer" that segregates the Application code from the Database.

The layer could be written as subroutines in your programming language or as Stored Routines in MySQL.

The application would ask the layer to perform, say, an API like Set_Foobar('a', 'b', '100') and the function would do whatever it takes.  Under the hood might be one UPDATE today, maybe 2 or 3 tomorrow.

With this technique, you have the freedom to rearrange the schema without touching the application code.  But you will have to change the layer.  And that will be easier than trying out how to implement the Trigger you are asking about.