With T&F, it’s also important to look at how many athletes a team usually carries at your events. Many schools recruit multiple distance and sprinters per year, but maybe bring in only 1-2 jumpers or throwers.
Regarding timing, coach support with admissions is usually given for ED/REA applications. Some coaches will still give support in RD, but would prefer to lock in recruits for ED. ED applications are usually due November 1 so prepare to have made a decision by then if given multiple offers. Pre-reads would be this summer followed by OVs in the early fall.
Good luck!