This is a pain in the 
, and I’m surprised I wasn’t notified about this topic before (because of the way I have my tracking preferences set). I found it from your post in the Wishlist topic you linked, and I found that topic because I was looking for information about the same issue myself.
I think the two methods you suggested (pulling the microSD card from the camera and inserting it into a PC to delete the time_lapse folder and/or its contents or reformatting the card) are the only ways to reclaim that space for other use (i.e., when the card is set for Continuous or Events Only recording), at least for now. That’s less than ideal.
FWIW, this issue is the same in the v2.50x app. I don’t know if it’s got more to do with Cam OG’s firmware or with the “Plugin Version” in the app, but I think it’s a good argument for a consistent UI for all Cam models in the app.