It's not a dumb question and be very careful seating bullets that close to the lands .005 jump as pressures will change. Start below max and work up. However, most do that - get at or close to the lands - to get better accuracy.
Yes the comparator measures off the ogive but I agree with the above and would also read the link below and be ready to change setups as bullets change. Also take multiple readings with the comparator as just a bit too much pressure can change the readings.
If you like the Hornady tools, you can send a couple of fired cartridges from your rifle and send them to Hornady and they will tap and drill that case so you have an exact match to the chamber of that rifle. Then when you change bullets you can use their other tool (can't remember the name but allows you to slide a bullet into the cartridge) to get a starting point for your dies as it will tell you where the lands are. Its the one that goes with the comparator. Sinclair makes some good tools as well. They are not perfect but
will speed up the process. You can also smoke the bullet or use a market to verify as mentioned to confirm. Hope that helps. http://www.accurateshooter.com/ballistics/tangent-vs-secant-vs-hybrid-ogive-bullets/