DPI systems in Turkey weren't even checking QUIC packets when I was there, let alone ECH. But, browsers usually start with TCP first to negotiate QUIC support,

DPI systems in Turkey weren't even checking QUIC packets when I was there, let alone ECH. But, browsers usually start with TCP first to negotiate QUIC support, which prevented bypass of web blocks. If you could force your browser to establish connection directly using QUIC, you could bypass all the blocks. That was last year though. Not sure about the current situation.