Why do you want to use a navto in your banner? You can just add the article or collection directly to your collection and have it show up in the browse page.
I'm not Mark, but I know I would like this feature to let users access the collection or article from multiple places on the browse page.
For instance, for some layouts I would like to include a small banner as a button to access a collection in addition to the collection card that is elsewhere on the browse page.
I am also not Mark, but would like to have that feature as well. Please note, that there are others who asked for that too: e.g. https://forums.adobe.com/thread/2010095
If you could link to a collection, you could use the same collection with different teaser images for example.
For us, as we have a lot of nested collections, we would like to build a consistent navigation on article and collection level. So we would like to build our own buttons for back and home that could be placed on articles an via banners in collections. We are also hoping that there will be a way to link to parent collections sometime, where we would add a button for in our nested collections.
For DPS Classic there was talked about offering a chromeless UI sometime, but it never came. I am very much hoping, that we can get rid of the very ugly top navigation bar in DPS 2015 in the future. But therefore we would need a way to offer the functions placed in there in another way first. Navto links in banners would be the first step.
I really don't think that it should be a lot of work to allow navto links on collection level, as the app already knows them. So why not add it? Would make quite a few people in here happy.