Hello!
It was brought to my attention by our kind dev @matburt that it is possible to upload and embed SGFs.
See this post in the welcome thread.
For example:
rxj-gokifu-18460725-Gennan_Inseki-Honinbo_Shusaku.sgf (6.9 KB)
d8fa06cf14ef541370766042859b22a2.sgf (263 Bytes)