In my opinion, testing only one of these is enough. Or is there a specific reason to suspect that changing from grid to map or from map to grid doesn't work even though chancing from grid to list works?

At integration level we don't need to target 100% coverage. In fact, in my opinion, that might be a bad idea. I think that testing one happy path and one unhappy path is enough. At the end of the day, we just want to test that the _integration_ are working as they should. Testing that each and every possible option/combination works should be done at unit level, where the test execution speed is a lot faster that in integration level.