Great suggestion VB. We've actually been putting together a communication channel strategy to see where best to host which comms. We can go through it together when you land but Telegram is definitely a possibility 
Now there exist bridges. I dont really know how you do it. Someone who own such channel should be asked how, or just googled. So all communication channels are linked. Slack, Telegram, Discord, IRC. And lest say I am on Slack and whatever I type people that are on IRC or Telegram or Discord can see. This bridges usually make huge boosts in activity on difference channels, since 1+1 = 3 always.