The uiua version makes more sense to me than the other even without arrays. It's closer to how my brain wants to understand what is happening: "multiply (the result of...) and 5" instead of "5 (2 and 1 added) multiplied."

The latter is kinda like "the old man the boat" where information occurring later in time changes the meaning of what comes prior.

I'm sure once things get complicated enough I would understand neither RtL or LtR with equal confusion, but the smaller cases seem very readable.