That was one of my first thoughts when really got into footed risers, and i bought an assortment of big cutters and set up a big 2hp router on my work bench rather than use a shaper. I used straight cutters, and spiral cutters both. You are absolutely right about tear out issues....There are times when running a shaper where the only way to avoid tear out is by "Climb cutting", and it is very dangerous to do hand feeding the material into the cutters. perfect formula for loosing fingers if ya ask me... The only way climb cutting can be done safely with a shaper is using a power feed that holds the lumber rather than using your hands. it's typically only done shaping molding on straight runs... doing radius work by hand with cutters on a shaper or on a large router table is flat out not recommended.... You can take that from someone with a lot of experience running these machines....
I would encourage you to pursue setting up a pattern sander in the future for doing riser footings, and don't even get started trying the shaper. Nothing but herat breaking, and dangerous work.
.05 cents worth... Kirk