"I find implicit variables most useful when there's a single value that needs to passed through multiple layers of function calls."
I'm finding a lot of uses for implicit variables. I've come to like them a lot. :P I'll note that there can only be one namespace active per executing code, so it made a lot of sense for me to use implicit variables.
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"When I have more than one value that I'm working with at a time, then I find implicit variables often become awkward, and I'd prefer to just specify the value explicitly."