What circuits? module, RF switch, crystal, flash, decoupling, DCDC circuit?
The imp003 is self-shielded (the module is silver-coated). This protects the RF xtal, RF switch etc.
The external components - 32kHz sleep clock, load switch, flash, etc do not need shielding. You will be using at least a 4 layer impedance control board for imp003 so should use best practices to ensure a “quiet” design (eg solid groundplane, good bypass placement, follow recommendations on DCDC layout, etc).