No way this is GDPR compliant. A mandatory Github login sends data to US servers. Even with the normal additional standard contract clauses it is at least dispu

No way this is GDPR compliant. A mandatory Github login sends data to US servers. Even with the normal additional standard contract clauses it is at least disputed, if this holds any grounds in a CJEU trial. Twilio, the owner of Segment.io is also a US company and will receive individual-related telemetry data, which should break with GDPR.