I love a 'Small Burnett' discussion.
Can only share my own soda-straw view of what worked and didn't work on my deer-dirt.
On good soil...it did great and continues to be a good productive crop 8+ years after seeding. In fact, it gets better with that tactic of not mowing until the seed heads mature ---late July/early August.
It is a fine stand in front of my barns. I'm happy.
I did try it on my poorest soil on the farm and it was not as satisfying.
I planted it last spring --late May 2020-- and we got no rain.
And the Burnett did nothing. For weeks and weeks and weeks.
Late in the summer when we did get moisture it began to get germination.
I have it growing in that spot now, but it is not anywhere near as robust as it is on my better ground.
I have some leftover seed and will 'nourish' that unsatisfying plot with a re-seeding come early August.
BTW....my neighbor, maybe 400yds away, has Burnett in their backyard and the deer mow it down to soil level.....year after year after year.
I am so impressed that it keeps coming back.
That the damn stuff survives that kind of predation.