Please allow for collaboration on PDF files directly.
How is it viable to have to open it in another app, save it as a new PDF and upload again on the Team, EVERY SINGLE TIME you want to modify (highlight, post a comment, add text ...) the file in the slightest???
I realised that 2 hours worth of editing are just gone simply because I needed to access another file on the app. Also, no warning message says “caution your changes will not be saved (because we didn’t think this was a useful feature to add)”, so you can imagine my disappointment and anger.
Please make this possible ASAP.