Though linear power supply designs tend to be bulkier, they definitely make a substantially smaller number of interference. As a result, If the unit can work efficiently without SMPS circuits, consider using a linear power supply to minimize the influence of EMI. Specifying a similar attenuation as from the plot https://betadinebuyonline22975.isblog.net/the-smart-trick-of-emi-rfi-filter-that-nobody-is-discussing-48514482