All support act same as a spring support with very high stiffness value.
Caesar default rigid restraint stiffness is 1.0E12 N/mm.
That means if we use 1.0E12 N load that support node point will deflect by one mm. or if we arrest one mm pipe thermal movement it will create 1.0E12 N load.
Similarly if we change stiffness deflection & load also change accordingly.
Piping overall stiffness depends on line routing.