Hi, 

Is telegram post embed supported? I tried and did not work.

If not, I was wondering about the reason, since Telegram is now probably top 5 most used social media and has so much content.

Also, is there a temporary workaround for this or any customization?

We support most services with oembed endpoints. Im not sure telegram however has an oembed endpoint. You would need to post within our suggestions area if you wish to see this added as a feature at some point in the future