Yes, thats a simple change if we must have this feature. But its the sort of thing easily overlooked as you read someone else's code. "Ah, a loop, yep, indexed, thats normal...."
My view is we really don't need this. I always consider a for loop as just a special case of a while or repeat loop with some default behavior built in. If we need to change that default behavior, we should just drop back to using a while or repeat loop and construct it our self. Its not hard.
Davo