When the FMC says to climb, you climb. FMC doesn't have the functionality of very gradual climb (as far as I know). Maybe you can play around with the step climbs (ours is usual RVSM) and set 100ft for the step climb (if it works?). Next flight I'll give it a try on the FMC.
I've seen "closely monitored V/S 500fpm" (100-200-300 to start, in reverse to level off) but that is only for passenger comfort, and of course cruise climb of 2000ft.