I should be very careful if I were you. There's the obvious issue of map shift, but apart from anything else the FMC's attempts to chase the next height/speed would in my view lead to an unstable and uncomfortable profile.
If you fly it with the flight system use VLOC and V/S or HDG SEL if that's all you've got. Better still fly the aircraft manually and enjoy one of the last pleasures of the job, a well flown and planned non-precision approach. Remember to adjust the altitudes on the chart for temperature as well, 10° below ISA = 4% higher! 300ft/nm always works well for the 3° g/p and if you can, draw up a little table of height/distance from a suitable DME is you have one.
Try doing the Kamikaze onto 13L at JFK with LNAV/VNAV and I assure you the airplane will have you on the edge of your seat!
Go on, your a pilot, fly the bloody thing!
