So after looking at the code, it's clearer to me what is going to be executed:
- Anything within a new lines block IF nothing is selected manually.

However, for new users working with single long queries it may not be clear especially if the partially executed query never finishes or causes an out of memory error.

I see now that if I highlight the whole block including the extra spaces given above then it will execute as one block.

Maybe if the "Run SQL" action highlighted the block of text that was actually executed, if there was no original selection would help to make it more clear? Or highlight after cancelling a query execution?