Sadly I can not comment on the current state of roku development patterns. I gave up on them a few years ago. There is no official twitch app for roku either, so I started investing and found a Github repo that you could compile and sideload your own from. After mine was remotely removed from my devices a few times I decided to move on from the roku bureaucracy.
I had watched for year as services and channels came an went from Roku. Reminded me when Direct TV was having problems with certain stations demanding more money to be on the service. Roku is not an open platform for developers. It a corporate advertising platform.
Sounds like conspiracy talk, and I don’t mean it like that. However I honestly don’t think of Roku as the small friendly platform it started as anymore. It has changed and I don’t think it is for the better.
We’ve looked at that in the past and the time delay caused by logging in at out of Google drive is just too much with the way ios is structured. Plus it doesn’t generally function like a simple drive location.
Finally on top of all the storage access complications , most apps dont save as actual files that can be saved to a destination folder, as ios doesn’t have a traditional file system. Usually you only get that kind of option with export, and then on ios it frequently is a preset list of destinations like email or airdrop. I haven’t seen a open send to so I can’t use mega.co or owncloud or others that I would like.
I totally admit I am not an apple expert, just a school technician that has tried to fit teacher/admin needs into establishing inflexible work flows with difficulties .