I thought I would post my thoughts on using the Lokee Ring
Cost: On sale for $200 CAD, normally $250 CAD.
Comfort: Very comfortable, i had no issues falling asleep with it on my finger at all.
Charging: Unfortunately does not use USB C, and uses USB micro (think old phone connection). However it does hold a charge for several nights which is a plus and is rechargeable. I was willing to put up with USB micro in exchange for this.
Data Retrieval: This was the part I was most unsure about, however it it's actually straight forward. After a night's sleep I open the app on my android phone, and the phone downloads the telemetry data over Bluetooth and then uploads it to the cloud. On my Windows PC once I open the app, O2 Insight Pro, it automatically downloads the data from the cloud. So there is no need for the PC to download the data from the device directly.
Sync'ing with Oscar: Since you already have the data on your PC, under the 'Data' menu choose Import 'Viatom/Wellue Data' and it will take care of itself.
Other Options: At this time I'm not aware of an oximeter that offers USB C, a rechargeable battery, and ease of use like this
Summary: All in all, I like having this in conjunction with my ResMed Airsense 11. I would recommend this. I hope this was helpful.