FWIW, I re-upped my CRP acres about 2 years ago and was pretty much obligated by the NRCS office to go with one of a couple options in terms of seed mix. I forget the exact seed breakdown, but it was pretty darned expensive once you start mixing in a lot of "fluffies" and various other species. Meanwhile, the dominant seed was CIR switch. It was my opinion from the start that the switch will overtake everything else in the mix in a year or two. 2019 was really the first year of the new mix growing and I can still see a "mix"...for now. I suspect that this year, or next, the switch will take over all the rest...which is pretty frustrating given how many $$'s went into it.
Now then, despite my misgivings about the wisdom, or lack thereof, of the particular seed mix I went with out of obligation...the greatly increased annual payment made me all better again. :) I suspect though that I will find out first hand what the deer will do with many acres of predominantly switch. I did go with the fire break buffers though that for the most part, run along the brush/treeline. So that will create quite a bit of "edge" cover too.