[nextgens]

What's the shortest chain-size that those free CAs can offer (assuming android>=5.0 devices)?

It would be great to have a tool somewhere that matches client handshakes & supported CAs vs server config & choice of CA chains

[Scott_Helme_]

They're all 3 certificates long (leaf/intermediate/root) apart from Let's Encrypt which, due to their cross-signature, are 4 certificates long for ECC.