The new 440 and later builds have a curated set of feeds and speeds which unfortunately, are at this time only available in a limited range of materials.
The full array of materials for auto-calculation were available last in build 433 — drop a line to support@carbide3d.com for download links.
You can of course enter any feed and speed rates you might wish into your own tool tables. See: Adding tools in CC440 and later for a start on doing so.
The router speed setting should match the feeds and speeds for your selection of endmill and material. Please see:
(there’s a row matching dial settings to RPMs at the bottom)
There’s an interactive version at: https://public.tableau.com/profile/willadams#!/vizhome/Carbide3DCNCFeedsandSpeeds/Sheet1?publish=yes
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 ).
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