They have black MPT capacitors
As Tom Thiel wrote, you should post a pic if you want a good answer. Did you mean “MKT”? Those are polyester caps and are likely lower quality than MKP (polypropylene). My FST-sourced OEM boards (China) had CYC brand MKT caps other than a polystyrene 1 uF bypass on the coax shunt (also CYC but, presumably, similar construction to Thiel’s custom polystyrene bypasses).