I've successfully planted stands of Switch a couple times with the following formula in zone 4.
1) Kill everything, plant RR beans for a season. I've done Switch with & without this step... Works much better with RR beans.
2) Drill Switch as near to May 10th as possible.
3) Wait 10-14 days then spray Gly & Atrazine or Simazine together.
4) Pray for rain.
5)The following spring, spray area with Gly, killing all cool season grasses as near to May 1st as possible. This should be done years 2 & 3. Fire serves the same purpose.
I prefer establishing stands of Switch only due the simplification of a challenging process (timing & herbicide). If you want forbs & flowers, drill them into sod after year 4 or 5 fire.
P.S. - The deer at my place LOVE the thick/tall monoculture of Switch. They use the more diverse grass mixtures but much less frequently.