Even if you practice ideal opsec possible given the permissions, the range of bitchat is maybe the length of a city block in ideal conditions. I think that is more of a false sense of security than a useful tool. LoRA blows that range out of the water and there is elevated repeater infrastructure in a lot of places, but still most people hear no one on their meshtastic node and ultimately it just goes in a drawer to be forgotten.
You can't fully. If you transmit wirelessly a motivated attacker can foxhunt you. Listeners are all safe from being triangulated which helps.
There are scales of trackable though. Precise location uploaded to the internet to data brokers r us is easier for the state than being forced to come out and foxhunt you personally. Also pay attention to the difference between broadcast type transmissions and handshake type transmissions. A ham radio can be on and never transmit. Many can have transmit disabled to prevent accidents. A Bluetooth, cell, or wifi device always transmits looking for peers the moment you turn it on.
If you need a level of opsec for a threat model where being personally hunted is an issue... Scheduled short checkins from random locations at random times. This is a broadcast not a conversation because of the safety of listeners. A ham foxhunt on 2m takes 2 hours or so depending, pros with better resources will be faster. You need to be able to complete transmission, tear down, and be gone before they can locate and get to you. You also need to be truly random. Keep in mind that from first key-down they have a rough idea of your location that gets more precise over time. Also they have travel time to get to the location they triangulated. This means that not getting caught doesn't mean they didn't know where you were. The implication here is that your random locations can't add up to drawing a 5 mile circle around your base. They also can't repeat because the hunters can stage teams close to known previous transmission sites.