USB-C PD, Voltage and Current of Power Adaptors
Small voltage difference is inconsequential for this kind of high power application. At least the power consumer should be aware of this difference, since all source parameters are clearly communicated to consumer over Power Delivery messaging protocol. The producer-consumer have an option to negotiate the best (optimal) power contract. If for some goofy reason the consumer doesn't like the extra 300 mV, it will reject the contract and negotiate another, close enoigh. So to answer your main question whether it is safe to interchange the supply bricks, then yes, it is safe.