The automagic feeds and speeds were removed from Carbide Create in 440 — that and later use a curated set of feeds and speeds which are stored in CSV files.
See https://www.youtube.com/watch?v=S9bceJxpqG0 for concepts on this and see the series #MaterialMonday: #MaterialMonday on YouTube for specifics.
You should test feeds and speeds in a piece of scrap using the technique at: https://precisebits.com/tutorials/calibrating_feeds_n_speeds.htm
Another consideration is Climb vs. Conventional Milling and tooling engagement — where possible avoid slotting and add geometry and cut as a pocket (Adding geometry to cut as a pocket with a finishing pass ) and consider leaving a roughing clearance and taking a finishing pass.
Extensive discussion at: Origin/consistency of chipload recommendations and https://shapeokoenthusiasts.gitbook.io/shapeoko-cnc-a-to-z/feeds-and-speeds-basics with a spreadsheet for this at: Speeds, Feeds, Power, and Force (SFPF) Calculator