I think that versions of Hypercard past v1.0 allowed for stacks of arbitrary window size; I know for a fact that I made up at least a few 1024x768 ones in v2.2.
You are correct in that I don't think it supported resizable windows without the use of some XCMD though.
You are correct in that I don't think it supported resizable windows without the use of some XCMD though.