Does Forte have feature, or in conjunction with 3rd party plugin, allowing compression of not velocity being sent to instrument modules?
You mean velocity scaling?
Not directly... if your plugin doesn't support it itself.
Maybe try something like adding a MIDIfx as an instrument and routing t's VMI output to another plugin (?). Or host somthing like energyXT as a plugin and insert a MIDIfx and the plugin into that.
Not pretty though...