Personally I think I would like a bit of Munich in a Helles. Is that completely out of place?
The Bohemian Dark in mine is essentially a light Munich. I don't know if it's wrong, but I like it. Not much color, but adds a real depth of malt flavor.
I mean, in the BJCPStyles if you search under helles there are really only three beers with helles in the title, Munich helles, helles bock, and German helles exportbeer.
I don’t think it is out of place at all unless you use too much Munich. Like Robert says, it adds a real depth of malt flavor.
Mine was still crisp like a lager, but had a nice malt character to complement the low ibus. It was probably a bit darker than the 5srm beer smith said it was supposed to be, but appearance is only 3 points. Still crystal clear and very bright.