There are some changes that are riskier than others, not because of the type of change, but because of the object. For example, some changes require rebuilding a table or index. This can be a simple process if there are a few hundred rows, but it's a risky, slow process if there are a few billion.
It would be nice to add a "risk" value to certain tables, so that when I see a list of changes, I can determine if this particular object ought to be separated out as a different deployment.
Interesting idea. You could of course build something rudimentary using tSQLt, but I'm wondering whether this could be implemented in Redgate tools as a configurable "high" deployment warning (high so it will can halt/pause an automated release process).