The next update to the Suricata 5.x package on pfSense will contain a new option for configuring Suricata to export performance stats over a Unix socket to Telegraf. It will support the input.suricata plugin.

Suricata can produce EVE JSON logs, and that data can be either written to a conventional text file or it can be made available to a Unix socket. So if someone produces a log data parser for EVE JSON, then Suricata can easily be adapted to feed data over the Unix socket. I am not familiar with Telegraf since I've never used it. So I don't know what it is capable of in terms of digesting Suricata's EVE JSON logs. The new feature I mentioned came from a Redmine Feature Request submitted a while back. And that request was specifically for Suricata performance stats (things like packets processed, packets dropped due to load, etc.).