How make HO easier or harder in Nokia in dedicated mode?

Yes, thats correct HOPI/S/G/L are idle mode paremeters and FMCS/I/G/L are dedicated mode mobility paremeters.
So, i think it should be it, did you have a look at those objects ( FMCS,FMCI,FMCG,FMCL)?

Also you can define the measurement offset on per adjacency basis.