I LOVE Front. 'slackifying' is such a bad reduction. Cross-channel communication, multi-seat enterprise support, CRM and automation would be better buzzwords.
My experience:
I spent a good amount of time thinking of ideas and building a plugin for our clients/use case. I think the concept would be killer if we can execute and get our clients to scale.
THENNNNN FB changed their rules and now I can't use Front to message outside of 24 hours.
I wouldn't bet/invest FB won't block all access to Messenger api once tools like Front are just gaining traction and or they have time to copy the best features into their own messenger tool.
My experience with the Front plugin api is kind of not great and missing basic features that were in version 1 but not in 2, and 1 is not supported anymore. And I think the RxJS doesn't help and like if you have to 'hack' a settimeout anyways to get and cache the state then what's the point...