Maximum weight on the Z-Axis

What is the maximum spindle weight that the z-axis can support? I’m thinking if the DW660 upgrade I’m about to do isn’t enough, could I step it up to a (monstrous) 2.25HP 10lb DW618 and make a custom mount for it? What are the limits?

Also wondering about that… Although the weight I see online for the DEWALT 2-1/4 HP EVS Router Motor Unit DW618M is 7.2 lbs (found on DeWALT’s website)

Look at the Dewalt DWP611 palm router. Thats what im upgrading to as soon as the new spindle mount comes out.