U got switch in some of those pics!!! Last mow- 10”-12” maybe mid August. Depending on weed pressure. personally, imo- I’d just do a spring spraying. The only residuals id run is atrazine, simazine, 2,4-d (which is a short residual & not enough by long shot). Since U now will have ESTABLISHED switch - early To mid may is about latest now- watch soil temps & Switch coming out of dormancy to assess latest time to spray. Ideally, just be couple weeks before soil temps are where natives will come out of dormancy. (New seeding is later spraying - which is not ur case now). Gly + atrazine/simazine + ams + 2,4-d end of April or beginning of may. If u seeded lil more in winter & u put enough atrazine/simazine down - u might be able walk away next year as “done”. Looks good! I think u have more there than u realize. Natives are always a Patience game & every year is filled with guys who think they have failures. Some do, but many don’t - especially those that followed correct steps. Most failures are from lack of following steps. Think u in good shape!