All those protocols are for hidden traffic, to prevent be detect and be blocked, if there have another Telegram developed protocol that can do this, it will very nice. I think using TLS as a transport layer is a good choice, it's safe, most of the traffic is TLS traffic, so putting a new protocol in it is not easy to detect. and TLS certificate is easy to get because Let's encrypt, create a TLS server is easy enough now.
Yes, you are right, if this feature is activated, people like you will stop selling filter breakers.
Instead of develop a protocol by yourself which will consume money, time and energy (like what has been done for mtproto), use an open-source community-driven tools such as shadowsocks (shadowsocks-rust / shadowsocks-libev), vmess, vless, trojan-cfw, NaiveProxy, etc. Generally speaking, vmess and vless written in GO which it makes them potentially be discovered in some rare cases but right now, they are great option with great community support! On the other hand, Naiveproxy has a great advantage, its written in c++ which makes it better against DPI but it doesnt support clouflare proxy which cause it to be useless in some cases
If you cant add these protocols at least add OpenVpn wich is globally verified and nearly every vpn company provide config files .