If it's an android phone, enable dev mode, install adb on your laptop, run an sshd under termux on the phone, and you should be able to set up iptables to forward packets from the laptop through the phone. The phone won't know that it's being used for tethering. Although I hadn't seen the stuff about packet TTL before. Maybe it's as simple as just adjusting that.
It may be easier to just run a VPN on the phone and route the traffic through it? WireGuard runs on Android. I've never tried configuring it to forward data through it though, but it should work.
If I recall correctly, they justify it by claiming they need to do deep packet inspection to balance traffic. There's a fuzzy line between them needing to optimize their network equipment and respecting privacy, and the rulings seem to favor the former.
This is what I've been using and it works for the most part other than the connection just dropping with too much use, only other thing I've used is PairVPN which had the same problem but was 100x worse. Is there something better around nowadays? I have a carrier locked phone and can't ROM or root