I'll take a listen to this in a bit, for better or worse, the flat k47 is flat. In real life certain frequencies get accentuated with closeness and vice versa with distance and the regular k47 is designed to maintain mid-presence in close range where The response itself would normally become u-shaped. I would suggest micing the flat 47 further. The mids might sound a bit hollow up close but for the very same reason I think they wouldn't sound overwhelming or stacked on top of each other in a live space at a distance like what may happen with the regular k47. If you want to use the flat k47 for close micing I would suggest a tube that rolls off both ends a bit and puts some bite into that region. This is probably why the 800 sounds so good with it? But I'm just spitballing