Like the spreadsheet HSMAdvisor calculates and displays total cutting force as the product of cutter radius and torque.
I don’t know about those trim routers, but my Bosch 1617 router has a deep race rear (thrust) bearing. But the Dewalt and Makita offer plunge bases, so they should be able to handle some axial forces as well. @Vince.Fab has cut an amazing amount of aluminum with his Makita. The workbook doesn’t really address entry or drilling but higher speeds are likely better if the cutter can handle it. I don’t know if either HSMAdvisor or Millalyzer properly address it either.
K-Factor is a constant that the workbook, HSMAdvisor, GWizard and likely most other calculators use to calculate cutting power from MRR. It’s just MRR divided by cutting power. My sense is that most/all K-Factors currently in use were derived from old machinist’s handbooks and probably aren’t very accurate for high speed machining. Millalyzer and likely some endmill manufacturers (like Kennametal) take cutting speed, chipload, detailed workpiece characteristics as well as cutter helix angle, rake angle, and edge radius, into consideration in their calculators.
IMO the complexity and number of variables involved emphasize how important it is to monitor and properly document actual achieved performance.