Zaino is pretty much tolerant of many non-Zaino products that do not contain alcohol (non-cleaning QD's). You can top with carnuaba if your desire (IMO adds nothing to appearance), use any alcohol-free QD and even top with products like UPP, OCW, etc withou effecting the Zaino base protection. One must only be cognitive that a good wash (Z7 will fill the bill), a Z6 wipe down will be necessary prior to adding additional layers of Z polishes (sealants). This subsequent layer(s) should be activated (Z1 or ZFX) for best bonding.
Also, topping with a non-Zaino system product should ONLY be performed after the Z sealants has fully cured.