The speed of the router needs to match the feed rate so as to maintain the desired chipload — the feeds and speeds usually indicate a desired RPM:
Official chart for Carbide Compact Router:
1: 10,000
(1.5: 12,000)
2: 14,000
(2.5: 16,000)
3: 18,000
(3.5: 20,500)
4: 23,000
(4.5: 25,000)
5: 27,000
(5.5: 29,500)
6: 32,000
Clearing out material with a large endmill, then cutting the remaining material w/ a smaller endmill is known as “Rest” machining — Carbide Create doesn’t have a direct feature supporting that: