I tested this last weekend as follows:
- Encoding and broadcasting with Flash Media Encoder
- Overlays with Livestream Studio (the web interface)
When I opened the web studio the broadcast started to clip. I checked the network statistics and you were right, the video was not uploaded twice. My conclusion was that my computer ran out of CPU capacity. When both FME and Livestream Studio were open the CPU capacity was 100% used.
Because I only have to update the graphics every 15 minutes I opened the web studio only when I had to change the graphics and then closed it. This way it (clipping) disturbed the broad only for a short period of time.
FME + studio is almost an ideal solution for me. The only caveat is that I can't get the overlay graphics for on-demand use. They won't (of course) be stored on my local files that I save from FME but for my surprise they are not stored in the clips that can be found in Livestream Studio on-demand library either. My plan was to download the FLV-files from the on-demand library (with the overlays) and then upload them to my own server with enough disk capacity.
So I'm still looking for a Perfect Solution (tm) that would satisfy the following needs
1) Free plan, my channel is a small non-profit organization
2) Lots of video-on-demand storage capacity (Livestream free plan 10GB is not enough)
3) Small overlay graphics that changes every 15 minutes but is visible all the time (we stream curling games and would like to show the scoreboard on the top of the screen)
4) The overlays saved for video-on-demand use
Now I'm missing #4.