Fuel Gauge Overdrive: How to Maximize Range

Hello everyone,

I'm stuck on the following problem and can't figure it out myself.

My US-made Ford now has an LPG (Liquefied Petroleum Gas) conversion system, and I would like the electronics to remain unaffected by it. This includes ensuring that the 'fuel level' indicator, which normally reads the fuel level from the gasoline tank, displays the correct fuel level data from the LPG tank while the vehicle is running on gas.
Otherwise, the onboard computer always complains that the fuel level in the tank isn't decreasing, even though I've already driven hundreds of kilometers.

So far, so good. With an older model, a simple switch box would have been enough.
Unfortunately, the 2006 Mustang uses a CAN bus for data transfer, which is why I ended up in this forum.

I'm looking for a component that can take a simple voltage signal (from the fuel tank) and convert it into digital data, which is then transmitted to the CAN bus in a way that mimics the original fuel level sensor.

Has something like this ever been done before, in a similar way?
If I've read the service documentation correctly, the level sensor is not connected to the high-speed motor bus. Wouldn't that make it less critical?

Do you think my plan is feasible?

Greetings.
Marcel.