As DDOS mitigation goes, TTL fingerprinting is pretty crude and unreliable. It’s sad that’s the best they think they can do, and it’s even more disappointing that they consider the Linux user community to be acceptable collateral damage.
However, they’re shot themselves in the foot with another group of users, this one fully and officially supported: users of the Mobile App. Android is based on a Linux kernel, so fingerprints the same as your systems. I “fixed” the mobile app on my rooted Nexus 6p by setting /proc/sys/net/ipv4/ip_default_ttl to 128 as well.