Hey that's a
really good idea.. in principle. But how would you power the Bluetooth chip and the sensor in the tank?

If you have to run a power line to the mod that defeats the benefit. And batteries in a tank? Doesn't sound too appealing..
Unless it was combined with wireless power - basically a flat metal panel on top of the mod, which could power a suitable atomizer in close proximity wirelessly. Then the bluetooth kicks in to send the data.
That would indeed allow a normal 510 connection with data and power transfer enabled for compatible in-tank-sensor attys.
No idea if it's cost effective though - wireless power transfer, Bluetooth in both tank and mod. Not that Bluetooth chips are expensive, but it's all extra cost and complexity versus just having a new connector. The wireless power would be the most complex part I guess. It's an interesting idea though - Innokin should think about it