As the title says, I tried switching from a RowList-based content grid to ZoomRowList. The layout seems to work all but the posters not appearing. My fading backgrounds are still working as before proving that the poster images have been fetched since I use the same image. I even set poster.visible = true in case the default was false with no success. It looks like the layout itself mimicks a Hero row that's activated for the currently focused row, while my previous layout of course just had a top Hero row. That's a lot of new settings to fiddle with just to achieve the new look, in my opinion. Anyway, here's where I'm at so far...
Since nobody replies to my messages here, I'll reply to myself with the answer.
ZoomRowList does not support the numRenderPasses, nor the renderPass field for the posters. Attempting to use renderPass will render blank posters. This contradicts Roku's documentation that ZoomRowList supports the same features as RowList.
I'm glad you were able to get the ZoomRowList to show your posters. Just to clarify, I believe the docs say that ZoomRowList has the same data model as RowList, but ZoomRowList extends ArrayGrid, not RowList, and thus they do have different fields.
Please let me know if there's any doc that does say that it supports the same features and we'll clarify that.