Assume an executable file has its set-user-id bit on.
When a process executes the executable file, it changes its effective user ID to the owner user ID of the executable file, after the kernel decides that the file can be executed via file access test. See https://stackoverflow.com/questions/41456225/how-and-when-does-exec-change-the-effective-user-id-when-the-set-user-id-is-s and What is the usage of set-user-ID of a program file?
Does that means that the owner user ID of the executable file can be one which doesn't pass the file access test performed by the kernel, even if the test has already been passed based on the original effective user ID of the process ?
Generally speaking, is it ever meaningful that the owner of an executable file doesn't have the execution permission?