Larger types are supported, there is A notion of tearing. According to JVM spec even long and double could tear, not sure about practical implications though

That's true for arrays of these value classes. Scalarization would help for larger local values though, since those would avoid pointer indirection for purely local values.

Surely it can't be that, it destroys basically the entire value proposition of value types, unless you use a preprocessor to write everything as SOA.

And one bit for null! So “smaller data types” means 32bits! Yay! It’s 1995 again!