As a Roblox developer, it is currently impossible to display tr.rbxcdn.com thumbnails of assets or users obtained from the Open Cloud API in-game.
If Roblox is able to address this issue, it would improve my development experience because it would allow me to display thumbnails of toolbox assets and more in (for example) a plugin.
My specific use case is a plugin that searches the toolbox for various assets. A lot of the assets do not have preview image IDs included, so my only option is to use the thumbnails.roblox.com endpoint, which returns images in the tr.rbxcdn.com domain. While this is perfect for off-roblox use-cases, these images do not show in-game, making it impossible to show a visual preview of certain assets (like music assets that have album covers).