I don't see any issue after an ONR wash if the vehicle is rinsed with just water post wash before application of Hydro2. UWW+ on the other hand leaves a substantial amount of protection on the surface that could potentially interfere with proper adhesion of Hydro2.
Hydr02 is meant to follow up your wash process, and you need to have the panel good and wet for application. You also need to use a strong stream of water to rinse and activate the product. So using a waterless wash is pretty much a waste with Hydr02, as you need to make the vehicle good and wet to use it. Also you do not need to clay or use a panel wipe prior to application. Hydr02 is an awesome product and can provide excellent results. Here are a few pics from the car I did this past weekend which was sealed off with Hydr02.